expression, godan verb (-u)
be deceived; be taken in; be tricked
Idiomatic expression meaning to be fooled or swindled, often implying a clever trick or scheme. Used in the passive sense even though the verb is active in form.
彼は詐欺師に一杯食わされた。
He was taken in by a con artist.
まんまと一杯食
You've been completely fooled, haven't you?