considerable, great, serious, untold (esp. BrE)
He was clearly intent on inflicting serious harm on someone.

irreparable, lasting, permanent
emotional, mental, physical, psychological
elderly people in danger of physical or emotional harm

economic, environmental

cause, do, inflict
The huge fall in exports has done a great deal of harm to the economy.

mean (sb), wish sb
I'm sorry if I upset you—I didn't mean any harm.
No one wishes you harm.

come to, suffer
I don't think he'll come to any harm if his mother is with him.

keep sb from, prevent, protect sb from, shield sb from
The children were removed from their parents to prevent harm to them.
She tried to shield her child from harm.

come to sb/sth
I don't want any harm to come to these pictures.

harm from
babies at risk of serious harm from their parents

harm to
the harm done to the environment

more harm than good
The drugs he was prescribed did him more harm than good.

out of harm's way
The younger children were kept out of harm's way.

seriously
Misusing drugs in pregnancy can seriously harm your baby.

deliberately
physically

intend to, want to
He claimed that he had not intended to harm the girl.

try to

Harm is used with these nouns as the object:
economy, environment, health, trade, wildlife