Crossword Genius

Mercury perhaps showing level temperature (6)

Ross

I believe the answer is:

planet

'mercury perhaps' is the definition.
(mercury is a kind of planet)

'level temperature' is the wordplay.
'level' becomes 'plane' (plane is a kind of level).
'temperature' becomes 't' (abbreviation).
'plane'+'t'='PLANET'

'showing' acts as a link.

(Other definitions for planet that I've seen before include "World" , "Sun's orbiter" , "Large celestial body" , "Is Pluto one?" , "Celestial body orbiting around a star" .)

I've seen this clue in The Independent.
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