Antonym of verb “holster”

Solution 1:

You’re probably thinking of draw¹, which is certainly used with this meaning:

To pull out (as a gun from a holster, or a tooth).

For example, you might say “the gunslinger drew his pistol”.

Solution 2:

Actually, it is unholster. I’m sure of it, because I’ve heard it a lot in those thousands of movies I’ve seen in my life.

Check the “unholster” Wiktionary entry¹ for further info.

Solution 3:

I would use the term draw, as in “He drew his gun to confront the robbers, then holstered it after they ran away.”

A dictionary entry and example from TheFreeDictionary:

To take or pull out: drew a gun from beneath the counter; drew out a fat wallet.¹

Solution 4:

I'd suggest that draw and unholster are subtly different- to draw a firearm is to remove it from the holster with intent to use it (or at least threaten such use); unholster would be more commonly used when surrendering or relinquishing a weapon, either for reasons of military discipline or to return to stores when no longer required.