Good as gold, for example (6)
I believe the answer is:
simile
'good as gold for example' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for simile that I've seen before include "as daft as a brush, say" , "as happy as Larry?" , "Figure of speech making straightforward comparison" , "Figure of speech, eg, as cool as a cucumber" , "device, comparatively speaking" .)