Opera star's worshipper (5)

I believe the answer is:

rasta

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

'worshipper' is the definition.
(I've seen this before)

'opera star's' is the wordplay.
'RASTA' is hidden within the letters.
However, I'm not sure how this is indicated.

Can you help me to learn more?

(Other definitions for rasta that I've seen before include "Black man" , "Disciple" , "One dreaded" , "religious follower" , "Adherent of sect originating in Jamaica" .)

I've seen this clue in The Sun.

Want a hint initially instead of a full solution? Install my app