clerical adj.

"a clergyman," 1620s (also in early use as an adjective), from Church Latin clericus "clergyman, priest," noun use of adjective meaning "priestly, belonging to the clerus;" from Ecclesiastical Greek klērikos "pertaining to an inheritance," but in Greek Christian jargon by 2c., "of the clergy, belonging to the clergy," as opposed to the laity; from klēros "a lot, allotment; piece of land; heritage, inheritance," originally "a shard or wood chip used in casting lots," related to klan "to break" (see clastic).

Klēros was used by early Greek Christians for matters relating to ministry, based on Deuteronomy xviii.2 reference to Levites as temple assistants: "Therefore shall they have no inheritance among their brethren: the Lord is their inheritance" (klēros being used as a translation of Hebrew nahalah "inheritance, lot"). Or else it is from the use of the word in Acts i:17. A word taken up in English after clerk (n.) shifted to its modern meaning.

suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).