harm
noun OPAL W
  /hɑːm/
  /hɑːrm/
[uncountable]Idioms - damage or injury that is caused by a person or an event
- He would never frighten anyone or cause them any harm.
 - The accused clearly intended to inflict harm on him.
 - He may look fierce, but he means no harm.
 - harm to somebody/something No definite harm to human health has been determined.
 - The court case will do serious harm to my business.
 - The accident could have been much worse; luckily no harm was done.
 - Don't worry, we'll see that the children come to no harm.
 - I can't say I like Mark very much, but I don't wish him any harm.
 - Hard work never did anyone any harm.
 - Look, we're just going out for a few drinks, where's the harm in that?
 - The treatment they gave him did him more harm than good.
 
Extra Examplessee also actual bodily harm, grievous bodily harm, self-harm- I don't think he'll come to any harm if his mother is with him.
 - I don't want any harm to come to these pictures.
 - I'm sorry if I upset you—I didn't mean any harm.
 - She tried to shield her child from harm.
 - The children were removed from their parents to prevent harm to them.
 - babies at risk of serious harm from their parents
 - elderly people in danger of physical or emotional harm
 - The region will suffer substantial economic harm as a result of this decision.
 
Oxford Collocations Dictionaryadjective- considerable
 - great
 - serious
 - …
 
- cause
 - do
 - inflict
 - …
 
- come to somebody/something
 
- harm from
 - harm to
 
- more harm than good
 - out of harm’s way
 
Word OriginOld English hearm (noun), hearmian (verb), of Germanic origin; related to German Harm and Old Norse harmr ‘grief, sorrow’. 
Idioms 
it wouldn’t do somebody any harm (to do something) 
- used to suggest that it would be a good idea for somebody to do something
- It wouldn't do you any harm to smarten yourself up.
 
 
no harm done 
- (informal) used to tell somebody not to worry because they have caused no serious damage or injury
- Forget it, Dave, no harm done.
 
 
out of harm’s way 
- in a safe place where somebody/something cannot be hurt or injured or do any damage to somebody/something
- She put the knife in a drawer, out of harm’s way.
 - I prefer the children to play in the garden where they’re out of harm’s way.
 
 
there is no harm in (somebody’s) doing something | it does no harm (for somebody) to do something 
- used to tell somebody that something is a good idea and will not cause any problems
- He may say no, but there's no harm in asking.
 - It does no harm to ask.