betrayer (n.)youdaoicibaDictYouDict
1520s, agent noun from betray (v.).
frayed (adj.)youdaoicibaDictYouDict
"worn by rubbing," 1814, past participle adjective from fray (v.).
prayer (n.)youdaoicibaDictYouDict
c. 1300, from Old French prier "prayer, petition, request" (12c., Modern French prière), from Medieval Latin precaria "petition, prayer," noun use of Latin adjective precaria, fem. of precarius "obtained by prayer, given as a favor," from precari "to ask, beg, pray" (see pray). Related: Prayers.

Prayer-book attested from 1590s; prayer-meeting from 1780. To not have a prayer "have no chance" is from 1941.
prayerful (adj.)youdaoicibaDictYouDict
1620s, from prayer + -ful. Related: Prayerfully; prayerfulness.