Crossword Genius

Risky sacrificing a rook that's valuable (8)

Ross

I believe the answer is:

precious

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

'that's valuable' is the definition.
(similar in meaning)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for precious that I've seen before include "Very fastidious" , "Much loved" , "Valuable, treasured" , "Of high worth or cost" , "Cherished or of high worth" .)

I've seen this clue in The Irish 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.