Mercury, for one (6)

I believe the answer is:
planet
'mercury for one' is the definition.
(Mercury is an example)
This is the entire clue.
(Other definitions for planet that I've seen before include "Neptune, for example" , "one of seven in suite" , "Eg, Mars, Venus" , "Celestial body that revolves around the sun" , "Substantial heavenly body" .)