Fill  —v. 1 (often foll. By with) make or become full. 2 occupy completely; spread over or through. 3 block up (a cavity in a tooth); drill and put a filling into (a decayed tooth). 4 appoint a person to hold or (of a person) hold (a post). 5 hold (an office). 6 carry out or supply (an order, commission, etc.). 7 occupy (vacant time). 8 (of a sail) be distended by wind. 9 (usu. As filling adj.) (esp. Of food) satisfy, satiate. —n. 1 as much as one wants or can bear (eat your fill). 2 enough to fill something.  fill the bill be suitable or adequate. Fill in 1 complete (a form, document, etc.). 2 a complete (a drawing etc.) Within an outline. B fill (an outline) in this way. 3 fill (a hole etc.) Completely. 4 (often foll. By for) act as a substitute. 5 occupy oneself during (spare time). 6 colloq. Inform (a person) more fully. 7 slang thrash, beat. Fill out 1 enlarge to the required size. 2 become enlarged or plump. 3 us fill in (a document etc.). Fill up 1 make or become completely full. 2 fill in (a document etc.). 3 fill the petrol tank of (a car etc.). [old english]