Where does “razor grinder” come from?

razor grinder (English) comes from English razor, from Middle English rasour, from Old French rasour, from Old French raser, from Vulgar Latin raso, from Latin rāsus, from Latin rādō, from Proto-Italic razdō — to scrape, scratch, gnaw.

razor grinder (English): A large brown cicada, Henicopsaltria eydouxii, of eastern Australia

Definitions

  1. A large brown cicada, Henicopsaltria eydouxii, of eastern Australia

Ancestry of “razor grinder”, step by step

razor grinder traces back through two separate lines of ancestry.

via English razor

StepLanguageWordMeaning
1EnglishrazorA keen-edged knife of peculiar shape, used in...
2Middle Englishrasourrazor
3Old Frenchrasour
4Old Frenchraserto shave
5Vulgar Latinrasodative masculine singular of rāsus; dative neuter...
6Latinrāsusscraped, shaved
7Latinrādōto scrape, shave, scratch
8Proto-Italicrazdō
9Proto-Indo-Europeanrh₁d-dʰ-
10Proto-Indo-Europeanreh₁d-to scrape, scratch, gnaw

via English grinder

StepLanguageWordMeaning
1EnglishgrinderOne who grinds something, such as the teeth; A...
2Middle Englishgrinder
3Old Englishgrindereone who or that which grinds, especially corn or...
4Old English-eremasculine agent suffix, originally applied only...
5Proto-West Germanic-ārī-er
6Proto-Germanic-ārijaz-er
7Latin-āriuser
8Proto-Italic*-āziosForms relational adjectives to nouns (and rarely numerals)
Every word from Proto-Indo-European reh₁d-