"Negative" match

Do you like challenges?

I'd like to know how do the following regexp:<br>
Match all strings wich exactly aren't (case ins.) "words", for example.

"some words" would match

"works" would match

"word" would match

etc.

but "words" wouldn't match

It is easy when the exp is a character, using [^a], [^b], etc. but, what about an entire expression

Try it as simple as possible, although I'm afraid it will result a monster regexp.

Thanks!

How about "/words/i" (or the ! thereof)?

What language, btw? In the regexes I've always used, a carat means "beginning" rather than "not."