The word for today is…
labile (adj) – 1. Open to change; readily changeable or unstable.
2. Fluctuating widely: labile hypertension.
3. Decomposing readily.
Source : The Free Dictionary
Etymology : We are confident that you won’t slip up or err in learning today’s word, despite its etymology. Labile was borrowed into English from French and can be traced back (by way of Middle French labile, meaning “prone to err”) to the Latin verb labi, meaning “to slip or fall.” Indeed, the first sense of labile in English was “prone to slip, err, or lapse,” but that usage is now obsolete. Other labi descendants in English include collapse, elapse, and prolapse, as well as lapse itself.