apodosis

Apodosis came into English through learned grammar and rhetoric. Its source is Ancient Greek apodosis, a noun meaning a giving back or return. The Greek word is built from apo, meaning away or back, and dosis, meaning a giving. By the Hellenistic period, grammarians had narrowed it to the clause that answers a condition.

Greek rhetorical teaching passed into late antique and Byzantine scholarship, and the term stayed technical. In grammatical description, apodosis was paired with protasis, the if-part and the then-part of a conditional sentence. That pairing appears in Greek commentaries and then in Latin school tradition. The sense was stable by late antiquity.

English took apodosis from that classical grammatical stream in the seventeenth century. Writers on syntax used it for the principal clause that completes a conditional statement, as in If he comes, we leave. The word never became common outside grammar, but it stayed precise. Its history is less about sound change than about the survival of a classroom term.

Today apodosis still names the result clause in a conditional construction. It also appears in rhetoric and literary analysis when a sentence deliberately withholds or delays its answering clause. The word keeps the old Greek idea of return: one clause calls, the other replies. It is the answer after the condition.