E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Conceited. The frog that tried to look as big as an ox was a botty frog (Norfolk). A similar word is swell, though not identical in meaning. Bumpkin and bumptious are of similar construction. (Welsh, bot, a round body, our bottle; both, the boss of a shield; bothel, a rotundity.)