Crossword Genius

Letter from largely grim French navy? (6-1)

Ross

I believe the answer is:

double-u

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

'letter' is the definition.
(I've seen this before)

I don't understand the rest of the clue.

Can you help me to learn more?

(Another definition for double-u that I've seen is " W".)

Want a hint initially instead of a full solution? Install my app