Where does “spy cop” come from?

spy cop (English) comes from English spy, from English -ing, from Old English -ing, from Old English -tūn, from Old English tūn, from Proto-West Germanic tūn, from Proto-Germanic tūną, from Gaulish dunum — smoke; mist, haze.

spy cop (English): An undercover police officer tasked with infiltrating a politically active group which is deemed to pose a risk of criminal activity, so as to allow the police to monitor the group's activities on an ongoing basis

Definitions

  1. An undercover police officer tasked with infiltrating a politically active group which is deemed to pose a risk of criminal activity, so as to allow the police to monitor the group's activities on an ongoing basis

Ancestry of “spy cop”, step by step

spy cop 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 cop

StepLanguageWordMeaning
1EnglishcopTo capture or arrest someone
2Middle Englishcopsummit; top, tip, topmost part; top of the head,...
3Old Englishcop
4Proto-West Germanic*koppvessel, container, bowl
5Proto-Germanickuppazround object; orb; vessel; container; bowl;...
6Proto-Indo-Europeangup-round object, knoll
7Proto-Indo-Europeangew-to bend, curve, arch, buckle; to bend, to curve;...
Every word from Proto-Indo-European dʰewh₂-Every word from Proto-Celtic dūnomEvery word from English -ing