mass noun
1- physical injury, especially that which is deliberately inflicted（尤指故意对身体的）伤害：
it's fine as long as no one is inflicting harm on anyone else.
只要没有人在伤害其他人就好。
1.1
- material damage（物资）损失, 损害：
it's unlikely to do much harm to the engine.
这不大可能会严重损坏发动机。
1.2
- actual or potential ill effect or danger（确实或可能的）坏处, 损害, 危险：
I can't see any harm in it.
我看不出有什么坏处。
with obj.
1- physically injure（在肉体上）伤害：
the villains didn't harm him.
那些流氓没有伤害他。
1.1
- damage the health of损害…的健康：
smoking when pregnant can harm your baby.
怀孕期间吸烟可能对婴儿有害。
1.2
- have an adverse effect on有损于, 不利于：
this could harm his World Cup prospects.
这会对他的世界杯赛不利。
短语
come to no harm
- be unhurt or undamaged没受伤, 没有受到损害。
do more harm than good
- inadvertently make a situation worse rather than better（非有意地）使情况恶化而不是好转; 成事不足, 败事有余。
no harm done
- used to reassure someone that what they have done has caused no real damage or problems［用于宽慰人］没有造成什么损失（或伤害）。
out of harm's way
- in a safe place在安全的地方。
词源
Old English hearm (noun), hearmian (verb), of Germanic origin; related to German Harm and Old Norse harmr 'grief, sorrow'.