Overweight visitor briefly hiding one's military overalls (8)
I believe the answer is:
fatigues
'military overalls' is the definition.
Although both the answer and definition are plural nouns, I don't see how one could define the other.
'overweight visitor briefly hiding one's' is the wordplay.
'overweight' becomes 'fat' (similar in meaning).
'visitor' becomes 'guest' (someone visiting a place).
'briefly' means to remove the last letter.
'hiding' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'fat'+'guest'='fatguest'
'fatguest' with its final letter taken off is 'fatgues'.
'fatgues' placed around 'i' is 'FATIGUES'.
Can you help me to learn more?
(Other definitions for fatigues that I've seen before include "Army gear" , "Military cover" , "Forces clothing" , "proves exhausting" , "bores" .)