from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Offensive An Uncle Tom.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. A diminutive of the male given name Thomas, also used as a formal male given name.
Possibly onomatopoeia, conflated with the given name, given the practice of giving objects such as Big Ben human names. Alternatively, it may derive from an inscription on the old bell used as metal to make the Great Tom of Oxford in 1680: In Thomæ laude resono bim bom sine fraude. (Wiktionary)