Partner's using it to plaster over five lounges (7)
I believe the answer is:
loiters
'lounges' is the definition.
('loiter' can be a synonym of 'lounge')
'partner's using it to plaster over five' is the wordplay.
I cannot really understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found within the answer.
'over' could be 'o' (cricket abbreviation) and 'o' is found in the answer.
'partner' could be 's' and 's' is located in the answer.
The remaining letters 'lier' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for loiters that I've seen before include "Hangs about idly" , "Fails to move on" , "Hangs around" , "Hangs about with toilers" , "dawdles" .)