What Does Suck-up Mean?

The phrase suck-up or suck up is slang meaning to behave obsequiously. In this sense of the term it is often used as a synonym for the word fawn. This expression is also used as a noun to describe an individual who is either ingratiating or fawning. For instance it could be used in the sentence 'The wealthy student tried his best to suck-up to the new teacher'.

Another expression using the word suck is the phrase suck in which means to take advantage of. It is used as a synonym for the words cheat, dupe, hoodwink and swindle. It could also mean to contract, tighten and flatten (the abdomen) in particular by inhaling deeply. The expression suck in may also simply mean drawing in as if by means of suction.

I dont know.
Not from me ask..