The two waiters exchanged a look whose meaning was clear to me.

what type of clause or phase is used?

I mean seriously.. People are not here to learn, they are here for ANSWERS. Ugh..

Adjective Clause

Study this carefully.

http://www.chompchomp.com/terms/clause.htm

Im dead lmao

Please look at the first example in her link. This is what you are.

OHHHHH, they told you!!!!

I was gonna tell a cripple joke but i cant stand those...

What is the clause? What kind to you think it is?

The sentence also has a prepositional phrase.

if i knew i would not ask

Please explain to me how to determine the answer im looking for