1Relating to or involving systasis; combining, synthetic.
2 historical That recommends something or someone; introductory; commendatory. Chiefly in "systatic letteror epistle" noun Christian Church a letter of introduction from a patriarch, priest, or other cleric.
Mid 17th century; earliest use found in Gilbert Watts (d. 1657), Church of England clergyman and translator. From post-classical Latin systaticus probative, confirmatory, of or for putting together, synthetic from ancient Greek συστατικός of or for putting together, component, introductory, commendatory, in Hellenistic Greek also drawing together, consolidating, probative, confirmatory from συν- + στατικός, after συνιστάναι to associate, put together, combine, bring together as friends, introduce.