Crossword Genius

One goes over handy tips to catch train (4,4)

Ross

I think it could be either:

Which length description are you looking for?:

8

4,4

nailfile

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'one goes over handy tips' is the definition.
I can't judge whether this defines the answer.

'catch train' is the wordplay.
'catch' becomes 'nail' (nail can mean to catch or arrest).
'train' becomes 'file' (file can mean a train or row of people).
'nail'+'file'='NAILFILE'

'to' is the link.

Can you help me to learn more?

(Other definitions for nailfile that I've seen before include "Manicure item" , "Manicurist's tool" .)

I've seen this clue in The Guardian.
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