Dismantle flimsy bathroom fixture? (5,5)
I believe the answer is:
strip light
'bathroom fixture?' is the definition.
(a bathroom might contain a strip light)
'dismantle flimsy' is the wordplay.
'dismantle' becomes 'strip' (synonyms).
'flimsy' becomes 'light' (I've seen this before).
'strip'+'light'='STRIP LIGHT'
(Other definitions for strip light that I've seen before include "source of illumination" , "tube for the office" .)