Way to a rock (5)
I believe the answer is:
stone
'rock' is the definition.
(synonyms)
'way to a' is the wordplay.
'way' becomes 'st'.
'to a' becomes 'one'.
'st'+'one'='STONE'
(Other definitions for stone that I've seen before include "Rock; hard seed" , "See 19" , "Piece of rock - weight" , "that one will 26d at 8a [FLING at HIGHLAND GAMES]" , "Small rock" .)