Consequently, cover reliable (5)
I believe the answer is:
solid
'reliable' is the definition.
(I've seen this before)
'consequently cover' is the wordplay.
'consequently' becomes 'so' (synonyms).
'cover' becomes 'lid' (lid is a kind of cover).
'so'+'lid'='SOLID'
(Other definitions for solid that I've seen before include "Hard; three dimensional" , "Hard and compact" , "Firm - sound - reliable" , "Reliable - substantial - pure" , "Sound; substantial" .)