volatile.

1. Liable to sudden, sometimes intense changes in mood or behavior.

2. Able to turn into vapor readily under the relevant conditions.

3. Liable to sharp, unpredictable changes in condition or value.

Use it for

Words that belong together

• volatile temper
• volatile relationship

On the page

The volatile relationship alternated between warmth and sudden quarrels.

Usage notes

Primary category: psychology / human behavior. Forms: Comparative more volatile; superlative most volatile when comparison is meaningful. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Established modern English lexical item. No separate regional spelling or grammatical inflection entry. Writing functions: character, behavior. Commonness: moderately common.