Boldly take on a complete crew (8)

I believe the answer is:

manfully

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

'boldly' is the definition.
Both the definition and answer are adverbs. Maybe there's an association between them I don't understand?

'on a complete crew' is the wordplay.
'on' says to put letters next to each other.
'a complete' becomes 'fully' (I can't justify this - if you can you should believe this answer much more).
'crew' becomes 'man' (I've seen this before).
'fully' put after 'man' is 'MANFULLY'.

'take' is the link.

Can you help me to learn more?

(Another definition for manfully that I've seen is " resolutely".)

I've seen this clue in The Irish News.

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.