pentecostarion

pentecostarion [pen-dee-kaws-tah-ree-awn; English pen-ti-ko-stair-ee-on] Word Origin noun, plural pen·te·cos·ta·ri·a [pen-dee-kaws-tah-ree-ah; English pen-ti-ko-stair-ee-uh] /ˌpɛn di kɔsˈtɑ ri ɑ; English ˌpɛn tɪ kɒˈstɛər i ə/, pen·te·cos·ta·ri·ons. Greek Orthodox Church.

1. a service book of offices for the period from Easter to the Sunday after Pentecost.

Origin of pentecostarion Late Greek pentēkostárion, equivalent to Greek pentēkost(ḗ) Pentecost + -arion Latin -ārium -ary