Borrowed from Northern Kurdish tirsîn (“to be afraid of”), from Proto-Iranian *tr̥šáti, from Proto-Indo-Iranian *tr̥šćáti, ultimately from Proto-Indo-European *tres-, first attested in the 1990s. According to Nişanyan the verb spread country-wide from Istanbul slang with Metin Kaçan's book Ağır Roman. Doublet of terör.