traitor (n.)

word-forming element meaning "across, beyond, through, on the other side of, to go beyond," from Latin trans (prep.) "across, over, beyond," perhaps originally present participle of a verb *trare-, meaning "to cross," from PIE *tra-, variant of root *tere- (2) "cross over, pass through, overcome." In chemical use indicating "a compound in which two characteristic groups are situated on opposite sides of an axis of a molecule" [Flood].

*dō-, Proto-Indo-European root meaning "to give."

It forms all or part of: add; anecdote; antidote; betray; condone; dacha; dado; data; date (n.1) "time;" dative; deodand; die (n.); donation; donative; donor; Dorian; Dorothy; dose; dowager; dower; dowry; edition; endow; Eudora; fedora; Isidore; mandate; Pandora; pardon; perdition; Polydorus; render; rent (n.1) "payment for use of property;" sacerdotal; samizdat; surrender; Theodore; Theodosia; tradition; traitor; treason; vend.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dadati "gives," danam "offering, present;" Old Persian dadatuv "let him give;" Greek didomi, didonai, "to give, offer," dōron "gift;" Latin dare "to give, grant, offer," donum "gift;" Armenian tam "to give;" Old Church Slavonic dati "give," dani "tribute;" Lithuanian duoti "to give," duonis "gift;" Old Irish dan "gift, endowment, talent," Welsh dawn "gift."