isn't

[iz-uh nt] /ˈɪz ənt/

contraction of is not.

Usage note

Pronunciation note

Isn't is often pronounced

[id-nt] /ˈɪd nt/ (Show IPA) in the South Midland and Southern U.S., with

[d] /d/ a stop consonant, substituting for

[z] /z/ a sibilant. This substitution results from an assimilatory process in which the tip of the tongue, in anticipation of the articulatory position for the following

[n] /n/ touches the upper alveolar ridge. This same process gives

[wuhd-nt] /ˈwʌd nt/ for wasn't and

[bid-nis] /ˈbɪd nɪs/ for business. These pronunciations are heard from speakers on all social levels.

Examples from the web for isn't

Print is a proper vehicle for the latter, but it isn't for the former.
Well, but he isn't sent to school for that-at any rate, not for that mainly.
It isn't becoming to you, really-except as an obvious pose.
Even though polystyrene forks are not biodegradable, keeping and reusing them isn't a great idea.
Sometimes the best defense isn't a good offense-it's a good diet.
Freezing organs isn't an option, as the cells dehydrate.
Elephant ears radiate heat to help keep these large animals cool, but sometimes that isn't enough.
If there isn't enough of the gas, temperatures go down.
Mutation isn't the only adverse effect of the radiation.
Making sense of the brain's mind-boggling complexity isn't easy.

British Dictionary definitions for isn't

isn't

/ˈɪzənt/

contraction

is not