Act dejected like a floor washer with heart disease (4)
I believe the answer is:
mope
'act dejected' is the definition.
(I've seen this in another clue)
'floor washer with heart disease' is the wordplay.
'floor washer' becomes 'mop' (I've seen this in another clue).
'with' says to put letters next to each other.
'heart' indicates the central letters.
The central letter of 'disease' is 'e'.
'mop'+'e'='MOPE'
'like a' acts as a link.
(Other definitions for mope that I've seen before include "Sulk over poem." , "Poem (anag.)" , "Go gloomily about" , "Pine - sulk" , "Misery guts" .)