Lunar domain — no sea, awfully lumpy (7)
I believe the answer is:
nodular
'lumpy' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
(Other definitions for nodular that I've seen before include "Lumpy" , "Having small lumps" , "Knobbly" , "Knotted" , "Like knots" .)