1A close-fitting cover for the blade of a knife or sword.

1. 1.1 A structure in living tissue which closely envelops another.
   （有机体的）鞘
   the fatty sheath around nerve fibres

   神经纤维周围的脂肪鞘。

   Example sentencesExamples

   • The distal open end of the sheath is guided through a punctured hole in the interatrial septum and into the left atrium.
   • For hundreds of years, scientists have studied plant cell walls - the protective sheaths that give plant cells shape and protect them from disease and dehydration.
   • Deep fascia provides muscle fibers with a protective outer sheath, and helps connect muscle to bone by way of ligaments.
   • The tendon, whose protective sheath ruptured Sept.26, runs around the back of his ankle.
   • Each individual, or zooid, is enclosed in a sheath of tissue, the zooecium, that in many species secretes a rigid skeleton of calcium carbonate.
   • The vascular bundle is surrounded by a sclerenchymatic sheath and parenchyma with chloroplasts.
   • The tumor infiltrated perineural sheaths and peripancreatic fatty tissue.
   • Therefore we can describe the outer part of the filament as a tubular structure, or a sheath, that surrounds either a cell chain or a lumen.
   • They travel to the brain and mount an assault on a substance called myelin, which acts as a protective sheath around nerve fibers.
   • The larva wriggles around for a day or two at this level until a loose sheath of epidermal tissue encloses it.
   • The median nerve and the tendon of palmaris profundus are ensheathed in a common sheath of connective tissue.
   • These bunches of axons are wrapped in myelin sheaths and bundled like electrical wire.
   • These replicate the sheaths that, like the insulation around a bundle of electrical wires, surround nerves in the body.
   • The notochord sheath is a collagenous connective tissue.
   • This sheath is often closely fitting but is not in close contact with the cells.
   • Injection of joints, bursae, tendon sheaths, and soft tissues of the human body is a useful diagnostic and therapeutic skill for family physicians.
   • All in all, the recent news is good because it means that the protective sheath around the nerve endings in his body, which were damaged in the attack, may be beginning to grow back.
   • There is a bunch of super thin muscle sheaths and tissue that surround our ribs which, when aggravated, take forever to heal.
   • The neurological condition is incurable and occurs when the protective sheath surrounding the nerve fibres in the brain and spinal cord is damaged.
   • It is the breakdown of the synovial tissue of tendon sheaths that gives rise to most ganglia.

   Synonyms

   covering, cover, case, casing, envelope, sleeve, wrapper

   technical tunica, capsule, fascia, neurilemma, epimysium, perimysium, perineurium, sarcolemma

   coleoptile, coleorhiza, ochrea
2. 1.2 A protective covering around an electric cable.
   （电缆的）护皮，护套
   Example sentencesExamples

   • In oil wells, the fiber is wrapped in a metal sheath, which deforms under pressure or temperature changes and squeezes the gratings.
   • This inside-outside electrode consists of a metal sheath surrounding a core of fluxing and alloying compounds.
   • The HF signal also jumps gaskets between pipe sections, bad telephone cable bonds, and small breaks in a cable's sheath.
   • Now, I am aware of the tricks like zip ties, sheaths, cramming cables into hidden areas, but if you swap out hardware as much as I do, this is an annoying thing to do.
   • The standard phone wire found in a residence is four untwisted, unshielded wires in a plastic sheath.
   • The linear symmetry of the gold-colored cable sheaths was especially important.
   • Films of silica act like the plastic sheath on copper cable, since silica is insulating.
   • It was also said that there were nicks on the sheath of the live cable at the ‘spur’, where the chair had been connected into the mains electricity supply.
   • The system includes a deflection device and a sheath and optionally uses a guidewire.
   • Installation is a breeze, and they even provide you with enough in the way of sheaths to keep your cables tidy if you need to.
3. 1.3 A woman's close-fitting dress.
   紧身女装
   Example sentencesExamples

   • Then, there's that generation who never wore anything more formal than a black sheath dress with a knit cardigan.
   • Sudanese model Alek Wek drew a wave of applause in a sweeping pink lame opera coat with fur collar, thrown over a silver sheath dress with giant embroidered palm leaves.
   • Seeing myself as a part of the room, I sewed a tight sheath dress from electric turquoise fabric that had a hairy-fringed surface, and presented Sidney with a bow tie I had made from silver vinyl.
   • The indispensable piece remains the sheath dress, interpreted à la nymphet mode by Alessandro dell'Acqua, and dramatically by Lawrence Steele, who created a luminous second skin of metallicized grey with lunar spangles.
   • The cute fuzzy add-on summons up old movie star allure to the most simple sheath dress and looks equally cute tossed over a tunic top and jeans.
   • Alexander McQueen has produced a grey tailored sheath dress with three-quarter sleeves and a bow detail under the bust.
   • The mutual friend brought a younger boy with long brown hair with a bright orange cummerbund and a green coat, which further clashed with her black and hot pink sheath dress.
   • While she has the hair, the face and the body to carry off a fitted purple silk sheath dress, I unfortunately look like a rugby prop forward in drag.
   • The skinny adolescent is dressed to kill in a black sheath dress, gloves and a straw pillbox hat with a veil.
   • Pink swirled over the white sheath dress, which billowed into a taffeta 1950's ingenue's gown.
   • In her twenties, she had styled red hair and was wearing a sheath dress, a single strand of pearls and a broad brimmed hat.
   • And, over the years, the sleek sheath dress became something of a red-carpet signature for her.
   • Her prom dress, a black sheath, sparkled in her bedroom.
   • Loren was beaming, looking flawless once again in a coppery sheath dress, with her silver blond hair spiraling down past her shoulders in waves.
   • As usual, she looked stunning in a sleeveless red sheath dress, her honey blonde hair held in place by a rose very similar to the one I was holding.
   • Long brown hair straight to her shoulders, black go-go boots and a sheath dress all in lavender clung to her too slim body.
   • His fingers gently undid the zipper of the plum colored silk sheath dress she wore and then slowly slid it off her shoulders, letting it fall effortlessly to the floor.
   • A simple sheath dress or suit with gorgeous shoes and accessories can also save you from maxing out a credit card for a one night only outfit and be appropriate too.
   • She looked fabulous from afar in an orange sheath dress with a sexy and intricate back cut-out.
   • Draped around her was a black silk sheath dress with deep red sleeves.
4. 1.4British A condom.
   阴茎套，避孕套
   Example sentencesExamples

   • In earlier times there had been advances in rubber sheaths but they were seen more as a protection against syphilis as opposed to a form of birth control.
   • The condom, or male sheath, was quite a late development.
   • Condoms have been around since 1350BC, according to Durex, when ancient Egyptian tribesmen used sheaths as protection against infection, injury and insect bites.
   • This bill aims to take away the criminalised aspect of that, and it de-penalises the aspect of having evidence of safe sex on the premises - that is, condoms, sheaths, diaphragms, and lubricants.
   • Protective and decorative penis sheaths were common among primitive societies.

   Synonyms

   condom

   contraceptive

   North American prophylactic

   British trademark Durex

   British informal johnny, something for the weekend

   North American informal rubber, safe, safety, skin

   British informal, dated French letter, Frenchy

   dated protective