Long whip-like outgrowths weaken Fitzgerald (8)

I believe the answer is:

flagella

I'm a little stuck... Click here to teach me more about this clue!

'long whip-like outgrowths' is the definition.
I can't tell whether this defines the answer.

'weaken fitzgerald' is the wordplay.
'weaken' becomes 'flag' (I've seen this in another clue).
'fitzgerald' becomes 'ella' (I've seen this in another clue).
'flag'+'ella'='FLAGELLA'

Can you help me to learn more?

(Other definitions for flagella that I've seen before include "Runners" , "whips" .)

I've seen this clue in the Sydney Morning Herald.

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