Hard hat accordingly put on (5)
I believe the answer is:
solid
'hard' is the definition.
(associated in meaning)
'hat accordingly put on' is the wordplay.
'hat' becomes 'lid' (synonyms).
'accordingly' becomes 'so' (synonyms).
'put on' is a charade indicator (letters next to each other).
'lid' after 'so' is 'SOLID'.
(Other definitions for solid that I've seen before include "from one getting pushed around" , "Not hollow or liquid" , "Hard; three dimensional" , "Of substance" , "Firm - substantial" .)