vitalrule

noun

UK /ˈvaɪ.təl.ruːl/

US /ˈvaɪ.təl.ruːl/

A very important rule that you must always follow.

Wearing a helmet is a vitalrule for riding a bike safely.

SYNONYMS

essential rule key rule must-follow rule critical rule core rule

RELATED WORDS

guideline regulation principle law standard

OTHER MEANINGS

2. A basic rule that keeps something working well.

Eating breakfast is a vitalrule for having energy at school.

3. A rule that is so important it cannot be broken.

Looking both ways before crossing is a vitalrule on busy streets.

4. The most important rule in a game or activity.

In chess, protecting your king is the vitalrule.