1
- mass noun physical suffering or discomfort caused by illness or injury病痛; 伤痛：
she's in great pain
她很疼
those who suffer from back pain.
那些腰背疼痛的人。
1.1
- count noun a feeling of marked discomfort in a particular part of the body疼痛：
he had severe pains in his stomach
他剧烈胃痛
chest pains.
胸部疼痛。
1.2
- mental suffering or distress痛苦; 悲痛：
the pain of loss.
失去亲友的痛苦。
1.3
- （亦作pain in the neck 或〈粗俚〉arse）[in sing.] informal an annoying or tedious person or thing〈非正式〉讨厌的人（或事）：
she's a pain.
她真讨厌。
2
pains
careful effort; great care or trouble辛苦, 努力; 苦心; 操心：she took pains to see that everyone ate well
她煞费苦心确保每个人都吃得好
he is at pains to point out that he isn't like that.
他刻意指出他不是那样的。
with obj.
1- cause mental or physical pain to使痛苦; 使疼痛：
it pains me to say this
这么说我很难过
her legs had been paining her.
她的双腿一直使她感到疼痛。
1.1
- no obj. chiefly N. Amer. (of a part of the body) hurt〈主北美〉（身体某一部分）感到疼痛：
sometimes my right hand would pain.
有时我的右手会感到疼痛。
短语
for one's pains
- informal as an unfairly bad return for efforts or trouble〈非正式〉作为对努力或辛苦的不公平的报酬：
he was sued for his pains.
他辛苦一场反遭起诉。
no pain, no gain
- chiefly N. Amer. suffering is necessary in order to achieve something〈主北美〉不劳则无获。
- ORIGIN: originally used as a slogan in fitness classes.
on（或 under）pain of
- the penalty for disobedience or shortcoming being违反则以…处罚：
they proscribed all such practices and observances on pain of death.
他们禁止所有这类习俗礼仪, 违者处死。
词源
Middle English （in the sense 'suffering inflicted as punishment for an offence'）： from Old French peine, from Latin poena 'penalty'， later 'pain'.