Mocking but not right, like some columns (5)
I believe the answer is:
ionic
'like some columns' is the definition.
(I know that column can be Ionic)
'mocking but not right' is the wordplay.
'mocking' becomes 'ironic' (I've seen this before).
'but not' indicates named letters should be taken away.
'right' becomes 'r' (common abbreviation).
'ironic' with 'r' removed is 'IONIC'.
(Other definitions for ionic that I've seen before include "A classical order of architecture" , "Relating to charged particles" , "Old Greek" , "Style of Greek column used for the British Museum and the US Capitol" , "Order for architects" .)