Wet horse, therefore yard providing blanket (5)
I believe the answer is:
soggy
'wet' is the definition.
(similar in meaning)
'horse therefore yard providing blanket' is the wordplay.
'horse' becomes 'gg' (geegee or GG is a childish term for a horse).
'therefore' becomes 'so' ('so' can mean 'consequently' or 'therefore').
'yard' becomes 'y' (abbreviation).
'providing blanket' is an insertion indicator (outside letters provide a blanket for others).
'so'+'y'='soy'
'gg' placed within 'soy' is 'SOGGY'.
(Other definitions for soggy that I've seen before include "Squelchy" , "Heavy and moist with liquid" , "sopping wet" , "Soaked" , "Waterlogged" .)