deh₃-no-
“thing given, gift, portion”donate, donor, dose, antidote
Extended form of *deh₃- giving Latin donāre/dosis, English donate, donor, dose, antidote, pardon.
Discussion
The PIE form *deh₃-no- (thing given, gift, portion) is a nominal derivative of the root *deh₃- (to give), formed with the suffix *-no- producing a result noun: "that which has been given." The root *deh₃- is one of the best-attested primary verbal roots in PIE, and this specific derivative produced the vocabulary of giving, gifting, and endowing.
Latin dōnum (gift, present) continues *deh₃-no- directly and gave English: donate (to give as a gift), donation, donor, pardon (per-dōnāre, to give completely — to forgive is to give away the debt of offense), and condone (con-dōnāre, to give together — to overlook an offense). The word dowry (from Latin dōtāre, to endow) preserves the giving-in-marriage sense.
Greek dṓron (δῶρον, "gift") preserves the root with the expected Greek treatment: Pandora (pan-dṓra, "all-gifted" — the first woman, to whom each god gave a gift), Theodore (theo-dōros, "god's gift" — one of the most common Greek personal names), and the female form Dorothy (Dōro-theá, "gift of god" — the same compound reversed). The name Isidore (Isi-dōros, "gift of Isis") shows the pattern extending to non-Greek deities.
Sanskrit dā́na- (gift, giving, charity) continues the root in Indo-Iranian and became a central ethical term in both Hindu and Buddhist traditions: dāna is the practice of generous giving, one of the foundational virtues in Buddhist ethics. The word entered English through these religious traditions.
The root *deh₃- itself (without the *-no- suffix) gave the verbal forms: Latin dare (to give — with its extraordinary derivative family: data, date, add, render, tradition), Greek didṓmi (I give), and Sanskrit dádāti (he gives). The reduplication in Greek and Sanskrit (di-dō-mi, da-dā-ti) preserves an ancient PIE present-tense pattern that confirms the root's extreme age.