What is the Latin word for supplication?

The usual Latin words for “supplication” are obsecrātiō, obtestātiō. The right choice depends on the sense; see the distinctions below.

English → Latin

“supplication” in Latin

obsecrātiōsupplication, entreaty; asseveration, protestation obtestātiōadjuring, conjuring; earnest entreaty, adjuration

The English word supplication itself goes back to Latin supplicō, through supplicatio.

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

supplication

obsecratio: obtestatio (a beseeching by things sacred or dear to anybody): preces supplices (humble entreaties). Earnest supplication, precum constantia (Tac., Germ., 8, 1): preces infimae (entreaties in the most submissive terms: ☞ supplicatio, with religious ceremonies = a Litany). Vid: also, PRAYER.

Quick answer

What is the Latin word for supplication?: The usual Latin words for “supplication” are obsecrātiō, obtestātiō. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.