Crossword Genius

Gullible senate shifts from the centre (4)

Ross

I believe the answer is:

naif

'gullible' is the definition.
(similar in meaning)

I cannot understand how the rest of the clue works.

(Other definitions for naif that I've seen before include "Unworldly" , "somewhat ingenuous" , "Inexperienced" , "unaffected simplicity" , "Unsophisticated" .)

I've seen this clue in The Guardian.
Want a hint initially instead of a full solution? Install my app