Where does “espion” come from?

espion (Italian) comes from Italian spione, from Vulgar Latin spio, from Frankish spehōn, from Proto-Germanic spehōną, from Proto-Indo-European speḱ- — to see, to look, to observe.

Ancestry of “espion”, step by step

StepLanguageWordMeaning
1Italianspionesneak, telltale; peeper
2Vulgar Latinspioto spy, espy; I spy; I espy
3Frankishspehōnto spy, watch; to peer, to look, to spy
4Proto-Germanicspehōnąto peer, look, spy
5Proto-Indo-Europeanspeḱ-to see, to look, to observe
Every word from Proto-Indo-European speḱ- →Every word from Proto-Germanic spehōną →Every word from Frankish spehōn →