Waterless all around, sow cross and somniferous (6)
I believe the answer is:
drowsy
'somniferous' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I can't see?
'waterless all around sow cross' is the wordplay.
'waterless' becomes 'dry' (similar in meaning).
'all around' is an insertion indicator.
'cross' indicates anagramming the letters (a cross or irritated version of the letters).
'sow' with letters rearranged gives 'ows'.
'dry' placed around 'ows' is 'DROWSY'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for drowsy that I've seen before include "Inclined to nod off" , "Sleepy, lethargic" , "Being rather tired" , "Comatose" , "Dull" .)