Precautious means careful. Precautionary is usually used to mean advice, as in "a precationary tale".
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Qu?nh Hu?nh"precautious" and "precautionary"'precautious' isn't used much. It means the same as 'cautious', which is used much more often.