means In the near future, before long — a vague, hopeful span of time that's always just ahead of now.

from From Old English 'sona,' meaning 'immediately, at once, right away.' Here's the quiet tragedy: 'soon' once meant *instantly* — no delay at all. Over the centuries it softened and slipped, the way a promise loosens with each repetition, until 'soon' no longer meant 'now' but merely 'sometime, eventually.' It's a cousin of similar words in old Germanic tongues. The word itself procrastinated its way from 'this very moment' to 'don't hold your breath.'