Reckon the boss is a boss in name only (10)
I believe the answer is:
figurehead
'boss in name only' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'reckon the boss' is the wordplay.
'reckon' becomes 'figure' (synonyms).
'the boss' becomes 'head' (I've seen this before).
'figure'+'head'='FIGUREHEAD'
'is a' acts as a link.
Can you help me to learn more?
(Other definitions for figurehead that I've seen before include "Leader that's powerless" , "Nominal leader without much power" , "carved decoration" , "bust from the navy" , "Front man" .)