"Impossible!"
'impossible' is the definition.
(associated in meaning)
This is the entire clue.
(Other definitions for hopeless that I've seen before include "Despairing, pessimistic" , "incurable" , "Inefficient" , "Desperate" , "Despairing - pathetic" .)
'impossible' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for no-go that I've seen before include "Impossible task for goon" , "Can't be done, not on" , "Entry to this area is forbidden (2-2)" , "Cancelled" , "Prohibited area" .)
(Other definitions for its that I've seen before include "Another form of 'tis" , "Belonging to something nonhuman" , "Neuter possessive pronoun" , "Belonging to a particular thing" , "Sit (anag.)" .)