Type of ray or blocker (4)
I believe the answer is:
beta
(Other definitions for beta that I've seen before include "software under test" , "Second Greek letter, B" , "Old character" , "2nd letter of Greek alphabet" , "Letter before gamma" .)
I believe the answer is:
beta
(Other definitions for beta that I've seen before include "software under test" , "Second Greek letter, B" , "Old character" , "2nd letter of Greek alphabet" , "Letter before gamma" .)