Where does “spyglass” come from?

Spyglass comes from English spy and glass, where glass derives from Middle English glas, Old English glæs, and Proto-Germanic glasą, ultimately from Proto-Indo-European gʰel-.

spyglass (English): A small portable telescope; A pair of binoculars

Definitions

  1. A small portable telescope; A pair of binoculars

Ancestry of “spyglass”, step by step

spyglass traces back through two separate lines of ancestry.

via English spy

StepLanguageWordMeaning
1EnglishspyA person who secretly watches and examines the...
2English-ingUsed to form gerunds, a type of verbal nouns,...
3Old English-ingForming nouns from verbs, indicating action,...
4Old English-tūnhomestead, village, town
5Old Englishtūnenclosure, yard; place; dwelling
6Proto-West Germanictūnfence
7Proto-Germanictūnąfence; enclosure
8Gaulishdunumfort; hill, hillfort
9Proto-Celticdūnomstronghold, rampart
10Proto-Indo-Europeandʰewh₂-smoke; mist, haze

via English glass

StepLanguageWordMeaning
1EnglishglassAn amorphous solid, often transparent substance...
2Scottish Gaelicglasgreen; grey; lock
3Middle Irishglas
4Old Irishglasgreen, greenish; blue, green-blue, grey-blue; the...
5Proto-Celticglastosgreen, blue
6Proto-Indo-Europeanǵʰl̥h₃stós
7Proto-Indo-Europeanǵʰelh₃-to flourish; green, yellow

Words derived from “spyglass

Every word from Proto-Indo-European dʰewh₂-Every word from Proto-Celtic dūnomEvery word from English -ing