Fix right level (4)
I believe the answer is:
tier
'level' is the definition.
(synonyms)
'fix right' is the wordplay.
'fix' becomes 'tie' (tying is a kind of fixing).
'right' becomes 'r' (common abbreviation).
'tie'+'r'='TIER'
(Other definitions for tier that I've seen before include "He might do sailor's knots" , "Row - one forming a knot" , "One who secures" , "One making knot - level" , "Rite about layer" .)