What does "いんやぁ" mean?


I've tried scouring through various Japanese dictionaries with no luck.

For some context: Person A has just heard person B and C have gotten married:

> いんやぁ~おめでたいよねぇ~！




Judging from the context you provided, 「いんやぁ」 would have to be the informal
pronunciation of 「いやあ」, which is an exclamation of surprise.

「ん」 quite often appears in a similar fashion for emphasis in colloquial
speech.

「すんごい」 for 「すごい」,

「うんめえ」 for 「うめえ」, etc.

![enter image description here](https://i.stack.imgur.com/7tDnr.jpg)

