1. characterized by rigor; rigidly severe or harsh, as people, rules, or discipline: rigorous laws.
2. severely exact or accurate; precise: rigorous research.
3. (of weather or climate) uncomfortably severe or harsh; extremely inclement.
4. Logic, Mathematics. logically valid.
"manners can be unrigorous."
This list can help you learn new vocabulary more quickly and be able explore other words more easily.