What does britch mean?
Considering this, what does too big for your britches mean?
Conceited, self-important, as in Ever since he won that tournament he's gotten too big for his britches, or There's no talking to Jill anymore—she's just too big for her boots. This metaphoric idiom alludes to becoming so “swollen” with conceit that one's pants or boots no longer fit. [ Late 1800s]
In this manner, where did the term britches come from?
Britches. The spelling britches is a spelling variant, not a corruption, dating from the 17th century. Presently, britches reflects a common pronunciation often used in casual speech to mean trousers or pants in many English-speaking parts of the world. Breeks is a Scots or northern English spelling and pronunciation.
Breeches are short trousers that extend to or below the knee. When speaking informally, breeches is a term that may refer to any trousers. Breeches is a plural noun, the preferred pronunciation is BRIchiz. Britches first came into use in 1571, it is an alternate spelling of breeches, and also, a less formal spelling.