a. 1. Not acknowledging favors; not expressing thankfulness; unthankful; ungrateful. [ 1913 Webster ]

That she may feel
How sharper than a serpent's tooth it is
To have a thankless child! Shak. [ 1913 Webster ]

2. Not obtaining or deserving thanks; unacceptable; as, a thankless task. [ 1913 Webster ]

To shepherd thankless, but by thieves that love the night allowed. Chapman. [ 1913 Webster ]

-- Thank"less*ly adv. -- Thank"less*ness, n. [ 1913 Webster ]

v. t. To give or dedicate in token of thanks. [ Obs. or R. ] Mede. [ 1913 Webster ]

n. One who gives thanks, or acknowledges a kindness. Barrow. [ 1913 Webster ]

n. 1. The act of rending thanks, or expressing gratitude for favors or mercies. [ 1913 Webster ]

Every creature of God is good, and nothing to be refused, if it be received with thanksgiving. 1 Tim. iv. 4. [ 1913 Webster ]

In the thanksgiving before meat. Shak. [ 1913 Webster ]

And taught by thee the Church prolongs
Her hymns of high thanksgiving still. Keble. [ 1913 Webster ]

2. A public acknowledgment or celebration of divine goodness; also, a day set apart for religious services, specially to acknowledge the goodness of God, either in any remarkable deliverance from calamities or danger, or in the ordinary dispensation of his bounties. [ 1913 Webster ]

☞ In the United States it is now customary for the President by proclamation to appoint annually a day (usually the last Thursday in November) of thanksgiving and praise to God for the mercies of the past year. This is an extension of the custom long prevailing in several States in which an annual Thanksgiving day has been appointed by proclamation of the governor. [ 1913 Webster ]