The most common and most likely answer to this crossword clue is the 6 letter word MANTRA
I've seen this crossword clue in The Times
M
A
N
T
R
A
More clues leading to the result MANTRA
- Watchword of guy painting in retirement
- Incantation provides chap with raised skill
- Sacred word in a set of books collected by male artist
- Chap put up paintings as aid to meditation
- Prayer from crew on capsized craft
- Phrase repeated in German translation
- Phrase that’s chanted in Roman tragedy
- Ray comes across right word to help concentration
- Snare hasn't closed — you can say that again!
- Sacred utterance from fellow on train leaving home
Buddy explains!

The straight part
We know that "Prayer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case prayer = mantra.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MANTRA mean?
MANTRA noun- The hymn portions of the Vedas; any passage of these used as a prayer.
- (originally Hinduism) A phrase repeated to assist concentration during meditation.
- (by extension) A slogan or phrase often repeated.