leav‧en¹ /ˈlevən/ (also leav‧en‧ing /ˈlevənɪŋ/) noun
[Date: 1300-1400; Language: Old French; Origin: levain, from Vulgar Latin levamen, from Latin levare 'to raise']

1. [uncountable] technical a substance, especially yeast, that is added to a mixture of flour and water so that it will swell and can be baked into bread ⇒ unleavened

2. [singular, uncountable] literary something that makes an event or situation less boring, serious, or sad

[TahlilGaran] Dictionary of Contemporary English ▲