Crossword Genius

Key frequently used to get in (5)

Ross

I believe the answer is:

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This clue could be a double definition.

'key frequently' is the first definition.
'enter' can be an answer for 'key' (key on a computer keyboard). I'm not certain of the 'frequently' bit.

'to get in' is the second definition.
('enter' can be a synonym of 'get in')

'used' is the link.

Can you help me to learn more?

(Other definitions for enter that I've seen before include "Inscribe", "Go/come in", "Break in", "Register (as a competitor)", "Record (in a log)".)

I've seen this clue in The Telegraph.