Solvent (7)
'solvent' is the definition.
(synonyms)
This is all the clue.
(Other definitions for thinner that I've seen before include "Slenderer" , "Solvent; less thick" , "Volatile liquid" , "Finer; turps, e.g." , "Dissoving agent" .)
'solvent' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for afloat that I've seen before include "On the surface" , "At sea - in circulation" , "On board a ship; out of difficulty" , "Bobbing along?" , "Buoyant: solvent" .)