Definition of garrisons:
(n) :
A permanent military post.
(n) :
The troops stationed at such a post.
(v) :
To assign troops to a military post.
(v) :
To occupy with troops.
(v) :
To convert into a military fort.
(n) :
(US, military, U.S. Space Force) A military unit, nominally headed by a colonel, equivalent to a USAF support wing, or an army regiment.