Timbre is a word that describes the tone or unique quality of a sound. If you play the same note on a piano and on a guitar, each note will have its own timbre.
Though an electric saw has its own timbre, as does the sound of a tree whooshing through the air, don't confuse timbre with "Timber!" the word you shout when chopping down trees. Timbre comes from the Greek word that means drum. Timber stems from an Old English word for building materials.