A jerk filling in hybrid puzzles (9)

I believe the answer is:

acrostics

'puzzles' is the definition.
(I know this)

'a jerk filling in hybrid' is the wordplay.
'jerk' becomes 'tic' (jerking movement by the body).
'filling in' means one lot of letters goes inside another.
'hybrid' becomes 'cross' (cross between two things).
'tic' inserted within 'cross' is 'crostics'.
'a'+'crostics'='ACROSTICS'

I've seen this clue in The Guardian.

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