Ground next to animal’s lair very wet (6)
I believe the answer is:
sodden
'very wet' is the definition.
'ground next to animal's lair' is the wordplay.
'ground' becomes 'sod' (both can mean a piece of earth).
'next to' says to put letters next to each other.
'animal's lair' becomes 'den' (I've seen this in another clue).
'sod'+'den'='SODDEN'
(Other definitions for sodden that I've seen before include "Drenched, really soaked" , "heavy with moisture" , "Thoroughly wet, soaked" , "Completely saturated" , "Waterlogged" .)