Rifts develop initially (5)

I believe the answer is:

first

'initially' is the definition.
(I've seen this in another clue)

'rifts develop' is the wordplay.
'develop' indicates an anagram.
'rifts' is an anagram of 'FIRST'.

(Other definitions for first that I've seen before include "& 2 Early new year arrivals bringing good luck" , "best" , "Top degree class" , "Most important" , "Highest degree" .)

I've seen this clue in The Mirror.

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