- The definition of an ingrate is a person who is ungrateful.
A friend who stays at your house for a month and then leaves without so much as a "thank you," is an example of an ingrate.
ingrate definition by Webster's New World
Origin: Middle English ingrat ; from Old French ; from Classical Latin ingratus, unpleasant, ungrateful ; from in-, not plush gratus, grateful: see grace
ingrate definition by American Heritage Dictionary
Origin: From Middle English ingrat, ungrateful, from Old French, from Latin ingrātus : in-, not; see in-1 + grātus, pleasing, thankful; see gwerə-2 in Indo-European roots.