Like net company associated with socialist, Sidney, in past (8)
I believe the answer is:
cobwebby
'like net' is the definition.
(a net might be described as cobwebby)
'company associated with socialist sidney in past' is the wordplay.
'company' becomes 'co' (abbreviation).
'associated with' means one lot of letters go next to another.
'socialist sidney' becomes 'Webb' (Sidney Webb, socialist thinker, 1859-1947).
'in' means one lot of letters goes inside another.
'past' becomes 'by' (as in years gone by).
'webb' put within 'by' is 'bwebby'.
'co'+'bwebby'='COBWEBBY'
(Other definitions for cobwebby that I've seen before include "Unclean (of corners in attics, perhaps?)" , "needing new broom" , "Like an unswept corner" , "very fine?" .)