Crossword Genius

Start off puzzles for dimwits (8)

Ross

I believe the answer is:

lummoxes

'dimwits' is the definition.
The answer and definition can be both people as well as being plural nouns.
Perhaps there's an association between them I don't understand?

I don't understand how the rest of the clue works.

I've seen this clue in The Times and The Sunday Times.
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