magpie

The word combines Mag, a nickname for Margaret once used to mean a chatterer, with the archaic word pie, meaning magpie, which came through Middle English and Old French from Latin pīca, tracing back to a Proto-Indo-European root meaning woodpecker or magpie.

Pie alone once meant magpie, but adding the personal nickname Mag turned it into the fuller, more familiar name we use today, replacing the older native English words agu and aguster (which survives as haggister).

It's a distant cousin of other pie-derived words, since pie itself came from Latin pīca, the root that gave English its old term for the bird before Mag was added to it.