Wakeful (5)
'wakeful' is the definition.
(synonyms)
This is all the clue.
(Other definitions for sleepless that I've seen before include "Film: '-- in Seattle'" , "Insomniac" , "Suffering from insomnia, not in the land of Nod" .)
'wakeful' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for alert that I've seen before include "Watchful, sharp" , "Vigilantly attentive" , "Watchful and observant" , "Signal danger" , "Watchfully awake" .)