Fill the bill' is an idiom that means to meet a requirement or expectation. The crossword solutions for this term are 'EAT, ' 'SATE, ' 'SERVE, ' 'SATISFY, ' 'FIT, ' and 'SUIT.' Eating, sating, serving, and satisfying all involve providing something to someone else, while fitting and suiting refer to meeting a certain standard or criteria. All of these words can be used to describe how someone or something can fill the bill.