What is a homonym for to gain?

There isn't a perfect homonym for "to gain" in the sense of acquiring something. However, the closest you can get is "to gain" itself, as it can also be used as a verb meaning "to increase" or "to get an advantage".

For example:

* "To gain weight" (to increase in size)

* "To gain ground" (to get an advantage)

While not a true homonym, this is the closest match in terms of meaning.