Inclination to nap in shelter among small trees with son (10)
I believe the answer is:
sleepiness
'inclination to nap' is the definition.
(tendency to sleep or nap)
'shelter among small trees with son' is the wordplay.
'shelter' becomes 'lee' (as in lee side, the side sheltered from wind).
'among' means one lot of letters goes inside another (inserted letters are placed among others).
'small' becomes 's' (abbreviation - e.g. clothes size).
'trees with' becomes 'pine' (I am not sure about the 'with' bit.).
'son' becomes 'ss' (I've seen this in other clues).
's'+'pine'='spine'
'lee' placed within 'spine' is 'sleepine'.
'sleepine'+'ss'='SLEEPINESS'
'in' is the link.
Can you help me to learn more?
(Other definitions for sleepiness that I've seen before include "torpor" , "dozy quality" .)