means That which actually is the case — facts and reality as opposed to falsehood or error, and the quality of conforming to them.

from From Old English trēowth, meaning faithfulness, loyalty, or fidelity to a promise — built on trēowe, 'faithful, trustworthy,' the same root that gives us 'true' and 'trust.' That older sense is telling: 'truth' first meant being true to someone (keeping faith) before it came to mean being true to the facts. It's a cousin of the Old Norse tryggð, 'good faith,' and traces back to a Proto-Germanic root tied to the steadfastness of a tree — something firm, deep-rooted, hard to move.