Latin mass (not the last) arranged, one thought to bring good fortune (8)
I believe the answer is:
talisman
'one thought to bring good fortune' is the definition.
I can't tell whether this defines the answer.
'latin mass not the last arranged' is the wordplay.
'not the last' means to remove the last letter.
'arranged' indicates anagramming the letters (letters rearranged).
'latin'+'mass'='latinmass'
'latinmass' with its final letter taken off is 'latinmas'.
'latinmas' anagrammed gives 'TALISMAN'.
Can you help me to learn more?
(Other definitions for talisman that I've seen before include "which is charming" , "Object believed to have magic powers" , "Amulet" , "Good luck token" , "Protective charm" .)