nutty

When describing flavor or scent, this term is typically positive and evokes a sense of warmth or richness. It is frequently used in culinary contexts to describe browned butter, certain cheeses, or roasted grains.

In a social or behavioral context, the word shifts to an informal register. While it can describe someone who is genuinely mentally unstable, it is more commonly used as a lighthearted or colloquial way to describe eccentric behavior or an absurd idea. It is less harsh than "insane" but more judgmental than "quirky."