I'd is defined as I had or I would.(contraction)
An example of I'd is what you would say if you have a preference of what you would like to do; "I'd rather say than leave."
The definition of the id is the unconscious part of the mind that causes primal needs to be met, according to Freudian theory.(noun)
An example of id is the instinct of fight or flight.
ID is defined as an abbreviation for identification.(abbreviation)
An example of an ID is a driver's license.
See id in Webster's New World College Dictionary
Origin: ModL < L, it, neut. sing. of is, he: used as transl. of Ger es, it
Origin: L idemthe same
Origin: < L -is, pl. -ides < Gr -is, pl. -idēs, patronymic suffixa thing belonging to or connected with; specif.,
Origin: < ModL -idae: see -idaean animal or plant belonging to a (specified) group: ephemerid
See id in American Heritage Dictionary 4
Origin: New Latin (translation of German Es, a special use of es, it, as a psychoanalytic term)
Origin: , from Latin, it; see i- in Indo-European roots.
Origin: Latin -is, -id-, feminine patronymic suff.
Origin: , from Greek.
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