to raise the level of (a liquid, powder, etc.) in (a container), usually bringing it to the brim of the container
(Economics, Accounting & Finance / Banking & Finance) to increase the benefits from (an insurance scheme), esp to increase a pension when a salary rise enables higher premiums to be paid
(Economics, Accounting & Finance / Banking & Finance) to add money to (a loan, bank account, etc.) in order to keep it at a constant or acceptable level
名词 top-up:
an amount added to something in order to raise it to or maintain it at a desired level