[n] - (British) an amount needed to restore something to its former level
noun an amount needed to restore something to its former level
To add liquid (finished wine of the same type, grape juice, sweetened water, or plain water) to a wine after racking it to replace any volume lost in the sediments left behind. One can also top up by adding sanitized marbles or glass pebbles to the carboy, thereby displacing the lost volume.