a Of a carbonated drink, with all or most of its carbon dioxide having come out of solution so that the drink no longer fizzes or contains any bubbles.
a (slang) Describing certain features, usually the breasts or buttocks, that are extremely small or not visible at all.
n (music) A note played a semitone lower than a natural, denoted by the symbol ♭ sign placed after the letter representing the note (e.g., B♭) or in front of the note symbol (e.g. ♭♪).
n (geometry) A subset of n-dimensional space that is congruent to a Euclidean space of lower dimension.