7 Answers

It is a unsettled stomach the same as nausea (feeling sick).

When your stomach is upset and you kind of feel like throwing up........

It's like...oh oh, quick...where's the bathroom?

feeling sick robertgrist has the best answer

queasy |?kw?z?|
adjective ( queasier , queasiest )
nauseated; feeling sick : in the morning he was still pale and queasy.
• inducing a feeling of nausea : the queasy swell of the boat.
• figurative slightly nervous or worried about something.
DERIVATIVES
queasily |-z?l?| adverb
queasiness noun
ORIGIN late Middle English queisy, coisy [causing nausea,] of uncertain origin; perhaps related to Old French coisier ‘to hurt.’

For instance " I have queasy hair or I ate to much queasy food.

Ducky

Oh no 1967...that's GREASY or maybe GREAZY!!!

Pythonlover gave the answer that makes the most sense to me.   Jhharlan's answer is right up there, too.  
My initial thought when I read your question was, "I think I'm going to puke." 

Ducky

"I think I'm going to puke" makes sense to me!

Ducky

Thank you for your very kind words above Bob!