Pulling a fast one' is an idiom that means to deceive or trick someone. It is often used in the context of a SCAM or CON, where someone is trying to take advantage of another person. The crossword solutions for this term are YANK (4 letters), SCAM (4 letters), CON (3 letters), GYP (3 letters), and LIE (3 letters). All of these words are related to the idea of deceiving someone, either through physical force, a SCAM, a CON, or a LIE.