I read two words recently, in different places, that are almost identical and seem to be used in similar contexts, so I looked up whether supplicant and suppliant were synonyms. They are closer than that, with cross-referencing definitions in the American Heritage Dictionary:
- suppliant: adj. Asking humbly and earnestly; beseeching. n. A supplicant.
- supplicant: n. One who supplicates; a suppliant. adj. Supplicating.
The AHD definition of supplicate:
- To ask for humbly or earnestly, as by praying.
- To make a humble entreaty to; beseech.
- To make a humble, earnest petition; beg.
All three have their roots in the Latin supplicāre. The etymology of supplicant: "From Latin supplicāns, supplicant-, present participle of supplicāre, meaning to kneel down." Suppliant comes from supplicāre, via a less direct path: "From Middle English, one who supplicates, from Old French, present participle of supplier, meaning to entreat, from Latin supplicāre." Supplicate has a Middle English predecessor: "Middle English supplicaten, from Latin supplicāre."