Verb: top up- To fill something to the brim or to a desired level
"Could you top up my coffee, please?"
Noun: top-up 'tóp,úpUsage: Brit, Cdn- An amount needed to restore something to its former level
"He needed a top-up of fuel before the long drive"
Derived forms: top-ups, topping up, tops up, topped up
Type of: indefinite quantity
Encyclopedia: Top up