Presbyterian (adj., n.) Look up Presbyterian at Dictionary.com
1640, in reference to the Scottish church governed by elders (as opposed to bishops), from presbyter "an elder in a church" (1590s), from Late Latin presbyter "an elder," from Greek presbyteros "an elder," also an adjective meaning "older," comparative of presbys "old" (see presby-).

Presbyterial was used from c.1600 in the sense "of or pertaining to a presbytery;" also from 1590s as "presbyterian" (adj.).