I. o ‧ ver ‧ night 1 /ˌəʊvəˈnaɪt $ ˌoʊvər-/ BrE AmE adverb
[ Word Family: noun : ↑ night , ↑ midnight , ↑ nightie ; adverb : ↑ overnight , ↑ nightly ; adjective : ↑ nightly , ↑ overnight ]
1 . for or during the night:
Pam’s staying overnight at my house.
2 . suddenly or surprisingly quickly:
He became a millionaire overnight.
happen/appear/change overnight
Reputations are not changed overnight.
► Do not talk about ‘an overnight’ because overnight is never a noun. It is either an adverb or an adjective.
II. o ‧ ver ‧ night 2 /ˈəʊvənaɪt $ ˈoʊvər-/ BrE AmE adjective
[ Word Family: noun : ↑ night , ↑ midnight , ↑ nightie ; adverb : ↑ overnight , ↑ nightly ; adjective : ↑ nightly , ↑ overnight ]
1 . happening during the night or for the night:
an overnight flight to Chicago
overnight accommodation in London
2 . happening surprisingly quickly:
The show was an overnight success.
his overnight decision to become a vegetarian