Like Great Bear, some mariners tell a rookie (7)

I believe the answer is:

stellar

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

'like great bear some mariners tell a rookie' is the definition.
I can't judge whether this defines the answer.

'some mariners tell a rookie' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'STELLAR' is hidden in the letters of 'mariners tell a rookie'.

Can you help me to learn more?

(Other definitions for stellar that I've seen before include "boss!" , "Starry" , "Like highlights" , "celebrity" , "Top-notch" .)

I've seen this clue in The Times.

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.