late 15c., from Latin truncatus "cut off," past participle of truncare "to maim, mutilate, cut off," from truncus "maimed, mutilated," also "trunk of a tree, trunk of the body," of uncertain origin, probably originally "mutilated, cut off," and perhaps from PIE root *tere- (2) "cross over, pass through, overcome." Related: Truncated; truncating.
early 15c., from Late Latin truncationem (nominative truncatio), noun of action from past-participle stem of truncare (see truncate).
*terə- Proto-Indo-European root meaning "cross over, pass through, overcome."
It forms all or part of: avatar; caravanserai; nectar; nectarine; nostril; seraglio; thrill; thorough; through; tranche; trans-; transient; transom; trench; truculent; truncate; trunk.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit tirah, Avestan taro "through, beyond;" Latin trans "beyond;" Old Irish tre, Welsh tra "through;" Old English þurh "through."