Crossword Genius

Giving lecture, do numbers that prime divides (8)

Ross

I believe the answer is:

speaking

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'giving lecture' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?

'do numbers that prime divides' is the wordplay.
'do numbers' becomes 'sing' (I've seen this in another clue).
'that prime' becomes 'peak' (synonyms).
'divides' means one lot of letters goes inside another (inserted letters divide the word).
'sing' enclosing 'peak' is 'SPEAKING'.

Can you help me to learn more?

(Other definitions for speaking that I've seen before include "Saying something" , "Conversing" , "oratory" , "Uttering" , "Talking" .)

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