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top–up

top–up /ˈtɑːpˌʌp/ noun
plural top–ups
top–up
/ˈtɑːpˌʌp/
noun
plural top–ups
Britannica Dictionary definition of TOP–UP
[count] British
: an amount of liquid that is added to make something full
: a payment that is made to bring an amount of money to a certain level