Drill bit used regularly, calmly and with attention to detail (10)

I believe the answer is:

diligently

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

'with attention to detail' is the definition.
I can't judge whether this defines the answer.

'drill bit used regularly calmly' is the wordplay.
'used regularly' indicates alternate letters.
'calmly' becomes 'gently' (I can't justify this - if you can you should give a lot more credence to this answer).
'drill'+'bit'='drillbit'
The alternate letters of 'drillbit' are 'dili'.
'dili'+'gently'='DILIGENTLY'

'and' acts as a link.

Can you help me to learn more?

(Other definitions for diligently that I've seen before include "with application" , "With meticulous care" .)

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.