The term "T-Bird" is a mid-20th century American English colloquial abbreviation for the Ford Thunderbird, a car first introduced in 1954. The car's name itself was inspired by the mythical Thunderbird, a powerful supernatural creature of immense size and strength in some Indigenous North American cultures, whose flapping wings were said to cause thunder. The nickname "T-Bird" logically condenses this name by taking the initial letter from "Thunder" and appending the full word "bird," creating a catchy and familiar shorthand that evokes both the car's official name and the imagery of speed and power associated with the mythical creature.

This is a compound nickname formed from the letter "T" (an abbreviation for "Thunder") and the common noun "bird". It is not a standard morpheme combination but a brand-specific colloquialism.