¹ sharp adjective

• having a thin edge that is able to cut things or a fine point that is able to make a hole in things
• sudden and quick
• involving a sudden change in direction

² sharp adverb

• exactly—used to refer to an exact time
• above the correct musical pitch
• suddenly

³ sharp noun

• a musical note that is one semitone higher than a specified note; also : a written symbol ♯ that is placed before a note to show that it should be played a semitone higher