Inconstaunte

Part of speech: adjective

Definitions

1. Liable to change often and without warning, lacking steadiness in feeling, purpose or behavior
2. Archaic form meaning likely to shift or vary, unreliable in loyalty, affection or resolve
3. Characterizing someone or something that is unsteady, wavering and prone to fickle changes over time

Etymology: The root is a picture of standing still. Latin "constare" meant "to stand firm" or "to stand together," formed from "con-" (together) and "stare" (to stand). A "constans" was something that stayed put. Add the negative prefix "in-" and you get "inconstans," something that does not stand firm. This spelling reached English through Old French "inconstant," which carried the same sense of wavering and changeable. The meaning moved from physical steadiness to steadiness of character: a person who will not hold to a course, a mood, or a promise.