Is without a little bit of support (5)
I believe the answer is:
joist
'support' is the definition.
(joist is a kind of support)
'is without a little bit' is the wordplay.
'without' indicates putting letters inside (some letters go outside or 'without' others).
'a little bit' becomes 'jot' (I've seen this in another clue).
'is' placed into 'jot' is 'JOIST'.
'of' acts as a link.
(Other definitions for joist that I've seen before include "Beam supporting floors and roofs" , "Timber or steel roof or floor support" .)