A top-up loan or payment is added to an amount of money in order to bring it up to a required level. Student grants will be frozen at existing levels and top-up loans made available
An additional or extra amount or portion that restores something to a former level
If you top something up, you make it full again when part of it has been used. We topped up the water tanks He topped her glass up after complaining she was a slow drinker. see also top-up