Which musical symbol means "lower in pitch"?

In music, flat (Italian bemolle for "soft B") means "lower in pitch". Flat is the opposite of sharp, which is a raising of pitch. In musical notation, flat means "lower in pitch by one semitone (half step)", notated using the symbol ♭ which is derived from a stylised lowercase 'b'. For instance, the music below has a key signature with three flats (indicating either E♭ major or C minor) and the note, D♭, has a flat accidental.

Double flats also exist, which look like double flat (similar to two flats, ♭♭) and lower a note by two semitones, or a whole step. The Unicode character (U+1D12B) in the Musical Symbols block represents the double-flat sign.