(亦作b)
(pl. Bs 或B's)
1
- the second letter of the alphabet英语字母表中第二个字母。
1.1
- denoting the second of two or more hypothetical people or things（假设的第二人或第二例）B, 乙。
1.2
- the second highest class of academic mark（学业成绩）B等, 乙等。
1.3
- (in the UK) denoting secondary road（英国）二级公路：
the B4248
4248号二级公路
B-roads.
二级公路。
1.4
- denoting the second-highest-earning socio-economic category for marketing purposes, including intermediate management and professional personnel（为市场营销而划分的社会经济类别中的）较高收入群体（包括中层管理人员和中级专业人员）。
1.5
b
Chess denoting the second file from the left, as viewed from White's side of the board【棋】（从执白方左边数过来的）第二列。
1.6
- （一般作b）the second fixed constant to appear in an algebraic equation（代数方程中的）第二已知量。
1.7
- Geology denoting a soil horizon of intermediate depth, typically the subsoil【地质】（中等深度）土壤层（尤指底土）。
1.8
- the human blood type (in the ABO system) containing the B antigen and lacking the A.B型血。
1.9
- with numeral denoting a series of international standard paper sizes each twice the area of the next, as B0, B1, B2, B3, B4, etc., B4 being 250 × 353mm（国际标准纸张规格）B型号纸（国际标准纸张型号代号, 如B0, B1, B2, B3, B4等, 每一号的面积是下一号的两倍, B4大小为250 × 353mm）。
2
- （一般作B）Music the seventh note of the diatonic scale of C major. (In the German system this note is called H, with B denoting B flat.)【乐】B音, B调（C大调音阶的第七音, 德国体系中该音称为H, B表示降B音）。
2.1
- a key based on a scale with B as its keynote.B音键。
短语
plan B
- an alternative strategy替补方案。
1.1
- Belgium (international vehicle registration).（国际车辆注册用语）同BELGIUM.
1.2
- bishop (used in recording moves in chess).［用于记录国际象棋棋步］同BISHOP:
Be5.
象e5.
1.3
- black (used in describing grades of pencil lead).用于表示铅笔芯硬度同BLACK:
2B pencils.
2B铅笔。
1.4
- bomber (in designations of US aircraft types).［用于标示美国飞机型号］同BOMBER:
a B52.
一架B52型轰炸机。