The Proto-Indo-European *dʰeih₂- "to see, look" in the metathesized form *dʰyeh₂- became Pali jhāna, related to Sanskrit ध्यान dhyāna "meditation". With the spread of Buddhism eastwards, the Pali word was borrowed into Mandarin as chán "quiet; silent meditation; Zen". This was borrowed into Japanese as zen (禅).
*dʰyeh₂-mn̥- became Greek σῆμα sēma "sign, mark, token", then σημαντικός sēmantikós "significant". English semantic was borrowed from French sémantique, which first appeared in 1897 in Essai de sémantique by Michel Bréal.
Pokorny suggests that *dʰeih₂- also became Greek θαυμάζω thaumázō "to wonder, marvel", the source of thaumaturge, and θέᾱ théā "viewing, play", the source of theatre.