rationale

Where does the word "rationale" come from? It comes from Latin rationalis, and was adopted directly into English (1650s).

Rationale’s story begins in Latin: rationalis meant “relating to reason.” Relating to reason, from ratio (reason, calculation). It reached English by 1650s as rationale. Settled as the English word for the underlying reasons behind something. Today, rationale means the underlying set of reasons or logical basis for a course of action.

1. Stage 1 · Latin · ancient rationalis "relating to reason", relating to reason, from ratio (reason, calculation).
2. Stage 2 · English · 1650s rationale "the underlying reasons or logical basis for something", settled as the English word for the underlying reasons behind something.