Out of condition (5)
'out of condition' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for unfit that I've seen before include "In poor condition" , "Ill-equipped" , "struggling to keep up?" , "Incompetent" , "Inapt" .)
'out of condition' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for flabby that I've seen before include "Sagging, not firm" , "Hanging loose (like excessive fat)" , "More than ample" , "Slack, loose (skin)" , "Flaccid" .)