Teams on radio? They think out of box, primarily (5)
I believe the answer is:
rains
'teams' is the definition.
Although both the answer and definition are verbs in their -s form, I cannot understand how one could define the other.
I can't explain the rest of the clue.
(Other definitions for rains that I've seen before include "Showers" , "Comes down from cloud" , "Falls in droplets" , "Tropical wet season" .)