a prescription drug that is provided again
"he got a refill of his prescription"
"the prescription specified only one refill"
a commercial product that refills a container with its appropriate contents
"he got a refill for his ball-point pen"
"he got a refill for his notebook"
A filling after the first.
"The barista asked if I would like to refill my coffee cup since it was getting low."
In plain English: A refill is an extra serving of something you already have, like getting more coffee when your first cup runs out.
"The machine started dispensing coffee for my refill after I tapped my card at the station."
fill something that had previously been emptied
"refill my glass, please"
To fill up once again.
"Please refill your glass when it runs empty so we can continue drinking our tea."
The word refill comes from combining the prefix re- meaning "again" with the verb fill. It entered English to describe the action of filling something up once more.