As adjectives the difference between precautious and precautionary
is that precautious
is taking precautions while precautionary
is of, pertaining to, or serving as a precaution.
As a noun precautionary is
(obsolete) a precaution.
Of, pertaining to, or serving as a precaution
- The article 3.3 of the states the precautionary principle .
(obsolete) A precaution.
* 1748 , Samuel Richardson, Clarissa
- Thou seest, Belford, by the above precautionaries , that I forget nothing.