I tossed coin, showing style (5)
I believe the answer is:
ionic
'style' is the definition.
(I have seen 'Architectural style ' mean 'ionic' so perhaps 'style' could also mean 'ionic')
'i tossed coin' is the wordplay.
'tossed' indicates anagramming the letters.
'coin' with letters rearranged gives 'onic'.
'i'+'onic'='IONIC'
'showing' acts as a link.
(Other definitions for ionic that I've seen before include "Like a sort of bond" , "One of five classical orders of architecture" , "Classical verse" , "Greek architectural style" , "Pertaining to charged particle" .)