words wholly unrelated
donkey & [any other word]
the first written use is actually from the dictionary of the vulgar tongue (1785) where it appeared as donkey dick. no credible derivation or cognate has yet been found. the leading contenders are:
- a familiar form of the name duncan.
- a diminutive of dun (dull greyish brown and a typical color of donkeys).
- potentially of imitative origin (could donkey be a longlost onomatopoetic animal?!?)
also of note is the original pronunciation most likely rhymed with monkey.

