Scintilla

[Sarah]

A spark; the least particle; an iota; a tittle. R. North.

[Sarah]

A tiny or scarcely detectable amount, the slightest particle, a trace, a spark, hardly anything. Perfect word for dieting or to describe an ex boyfriend's penis.

[Gregory]

a very small amount of something:

[Britney]

A tiny trace or spark of a specified quality or feeling.