The jug of milk half full, so he took a glass of water and *.
I am not sure if there's a word for it, but I guess if there lacks a word for it there's a phrase that sounds better than "fill it to the required quantity". What word or phrase would you use?
Best Answer
If you specifically mean the vessel has some liquid in, but not enough, and you are adding more liquid - the same sort, or a different one - to fill it to a required level, that's the phrasal verb to top up1.
Phrased a bit more naturally:
(Topping it up with water sound a bit weird, but okay)
You get this in cocktail recipes:
(From The Guardian's beginner's guide to making cocktails)
You can also use that for materials other than liquids - you might talk about topping up your liquor cabinet, or your supply of pasta. It can even be for immaterial things, like topping up your mobile (cellular) phone's credit, or topping up your bank account by selling unwanted possessions. In these other contexts, it doesn't usually carry the connotation of filling to a specified level, it just means that you think there's not enough and you should get some more.
1: At least, in British English; American English apparently uses "top off", which we use... differently, in British English.