Wiktionary
top off
vb. 1 (context US English English) to fill completely; to fill or refill the final portion of something not empty 2 to complete, to put the finishing touch to (something)
WordNet
top off
v. finish up or conclude; "They topped off their dinner with a cognac"; "top the evening with champagne" [syn: top]
fill to the point of almost overflowing; "She topped off the cup"