BビーMeanings1nounB; bThe letter B itself, used as a noun (e.g., grades, blood types, musical notes, or labels).彼かれの成せい績せきはオールBだ。His grades are all B's.血けつ液えき型がたはB型びーがたです。2nounbasement floorabbreviationAbbreviation used in floor numbering, as in B1F (basement first floor).会かい場じょうはB1Fです。The venue is on the B1 floor.