11 letters · 14 points in Scrabble
noun someone who takes up a position surreptitiously for the purpose of espionage
noun an intruder (as troops) with hostile intent
originEtymology tree English infiltrate Old French -eorbor. Middle English -our Proto-Indo-European *-tōr Proto-Italic *-tōr Latin -torlbor. English -or English infiltrator From infiltrate + -or.
Etymology from Wiktionary, CC BY-SA 3.0