A very long time beginning to make a gesture (4)

I believe the answer is:

ages

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'a very long time' is the definition.
(ages can informally mean a long period)

I don't understand the rest of the clue.

Can you help me to learn more?

(Other definitions for ages that I've seen before include "Indefinitely long time" , "Times" , "(What seems) a very long time" , "Matures" , "Rock of - - (hymn)" .)

I've seen this clue in The Irish News.

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