Unenthusiastic (8)
'unenthusiastic' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for lukewarm that I've seen before include "Not enthusiastic like tepid water" , "Little enthusiasm" , "Not very keen" , "Not having high temperature" , "Moist" .)
'unenthusiastic' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for cool that I've seen before include "Pleasantly fresh, not too cold" , "Chilled" , "Modern calmness, brrr!" , "Calm; chilly" , "Moderately cold" .)