Inattentive -- shake please! (6)
I believe the answer is:
asleep
'inattentive' is the definition.
(I've seen this before)
'shake please' is the wordplay.
'shake' indicates an anagram.
'please' with letters rearranged gives 'ASLEEP'.
(Other definitions for asleep that I've seen before include "not paying attention" , "Please be at rest (6)." , "Having forty winks" , "Out for the count" , "in bed?" .)