The frog most readers probably imagine comes from a source that — not surprisingly — meant to hop. This Proto-Indo-European root made its way into Russian, Sanskrit, Dutch, German, Old Norse, & Old English, & is now defined as an insect-eating anuran amphibian of the family Ranidae.
But the word frog does not stop at amphibians.
Like buttons, zippers & Velcro, frogs can be used as garment closures (a decorative cord fastening). This meaning came about in the mid-late 1700s. It grew out of an earlier 1700s meaning, an attachment on a belt to hold the scabbard of a sword. No one is certain of the root of this meaning of frog.
Florists use frogs in the bottom of vases to support plant stems in flower arrangements. This meaning most likely came from the similarity of the rounded backs of early plant-stem-holders to the rounded backs of insect-eating anuran amphibians.
The bit of a violin bow the violin player grips is also called a frog (the jury is out regarding this meaning’s origin).
And the word frog has been used as a slur against French people, due to an English stereotype regarding people’s diets in France.
And then there are frog youth: In 1877, a small child might have been referred to as a tad. Etymologists are moderately sure tad was a shortened form of tadpole, which was born of the word tadde, an alternate form of toad. Toad came to English in the 1300s from nobody-knows-where, & was added to the Middle German word poll, meaning head. It wasn’t until 1915 that tad began to mean a small bit. Polliwog, another term for frog youth, showed up in the 1400s from a word meaning wiggle added to poll-, that German word for head that also appears in the word tadpole.
Frogs do appear to hop rampant, eh?
My thanks go out to this week’s sources: Merriam Webster, Collins Dictionary, Wordnik, & Etymonline.