Supplicate, v. t. [imp. & p. p. Supplicated; p. pr. & vb. n. Supplicating.]
Etymology: [L. supplicatus, p.p. of supplicare to supplicate; of uncertain origin, cf. supplex, supplicis, humbly begging or entreating; perhaps fr. sub under + a word akin to placare to reconcile, appease (cf. Placable), or fr. sub under + plicare to fold, whence the idea of bending the knees (cf. Ply, v. t.). Cf. Supple.]
1. To entreat for; to seek by earnest prayer; to ask for earnestly and humbly; as, to supplicate blessings on Christian efforts to spread the gospel.
2. To address in prayer; to entreat as a supplicant; as, to supplicate the Deity.
Syn. -- To beseech; entreat; beg; petition; implore; importune; solicit; crave. See Beseech.
1 other Webster entry under this spelling
Supplicate, v. i.
To make petition with earnestness and submission; to implore. A man can not brook to supplicate or beg. Bacon.
Shades of meaning
Fernald has no entry of its own for supplicate; he lists it under ask, pray.
Where he writes about it:
To implore is to ask with weeping and lamentation; to supplicate is to ask, as it were, on bended knees. — from ask
Beseech and entreat express great earnestness of petition; implore and supplicate denote the utmost fervency and intensity, supplicate implying also humility. — from pray