Tries alternate rituals (5)
I believe the answer is:
rites
'rituals' is the definition.
('rite' can be a synonym of 'ritual')
'tries alternate' is the wordplay.
'tries' can be anagrammed to 'RITES'.
However, I'm not sure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for rites that I've seen before include "Social customs" , "Customary observances, religious say" , "Prescribed religious ceremonies" , "Tires of religious ceremonies" , "offices" .)