Expressions (phrases, clauses, etc.), Godan verb with 'su' ending
to play a trick on; to cheat; to deceive; to dupe
あのカーディーラーはこの中古のトヨタが調子がいいなどと、まんまと一杯くわせやがった。That car dealer gave me a bum steer when he told me this used Toyota was in good condition.
Also written いっぱい食わす【いっぱいくわす】