Taking shelter inside agent's almost out (6)
I believe the answer is:
sleepy
'out' is the definition.
(thesaurus)
'taking shelter inside agent's almost' is the wordplay.
'taking shelter' becomes 'lee' (as in lee side, the side sheltered from wind. I am not sure about the 'taking' bit.).
'inside' indicates putting letters inside.
'agent's' becomes 'spy's' (spy is a kind of agent).
'almost' means to remove the last letter (most of the word but not all of it).
'spys' with its last letter taken off is 'spy'.
'lee' inserted within 'spy' is 'SLEEPY'.
Can you help me to learn more?
(Other definitions for sleepy that I've seen before include "Unwakeful" , "Feeling like having a snooze" , "in retirement?" , "One of the Seven Dwarfs" , "Ready to nod off" .)