well there are quite a few antonyms for customary. You could use abnormal, different, or irregular.
average everyday ordinary typical expected run-of-the-mill commonplace unexceptional unremarkable usual familiar predictable common customary natural
It is a customary unit.
To the Adams Family, it isn't customary to leave a tip for the waiter.
yes it is customary
The antonym of the word 'synonym' is 'antonym'.
customary
It is a customary unit.
An antonym means "opposite". So an antonym for the word synonym is antonym.
customary
Yes, customary is the correct spelling.
it is in the us customary unit or else we wouldnt be learning about. there for it is in the us customary unit.
what is customary land tenure system