top-up

Adjective

• That serves as an addition

Noun

• An addition.
• A serving of drink used to top up an existing glass.
• An additional premium paid over the initial premium in order to increase benefit values.
• Additional credit purchased for a mobile phone.
• A dose of epidural anesthetic added to previously injected spinal anesthetic in combined spinal-epidural anesthesia
• The situation where a student who holds a qualification equivalent to part of a degree course is then accepted onto a degree course at an intermediate point, without having to start it from the beginning.