Crossword Genius

Medieval instrument used to determine the altitude of the sun (9)

Ross

I believe the answer is:

astrolabe

(Other definitions for astrolabe that I've seen before include "Navigation aid" , "navigational aid" , "Navigational device" , "Old instrument for astronomical measurements" , "Early astronomical instrument" .)

I've seen this clue in The Mirror.
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.