用法:
1 (a) [U] condition of being male or female; gender 性别; 性:
differences of sex 性的区别 *
What sex is your dog? 你的狗是公的还是母的? *
Everyone is welcome, regardless of age or sex. 欢迎大家, 无论男女老幼一律欢迎. *
[attrib 作定语] sex discrimination, ie treating sb differently because of his/her sex 性别歧视.
(b) [C] either of the two main groups (male and female) into which living things are placed according to their functions in the process of reproduction (reproduce 4) 男性, 女性, 雄性, 雌性（指生殖功能而言的）:
Is this behaviour typical of the male sex? 这种行为是雄性特有的吗? *
There has always been some conflict between the sexes. 两性之间从来就有矛盾.

用法:
2 [U] ~ (with sb) sexual intercourse 性交:
have sex (with sb) （与某人）性交 *
They often had sex together. 他们常发生性关系. *
[attrib 作定语] sex organs, ie penis, vagina, etc 性器官.

用法:
3 [U] activities that lead to and include sexual intercourse; mutual physical attraction between people 性行为; 性吸引; 性感:
a film with lots of sex in it 有很多性行为镜头的电影 *
During puberty, young people become more interested in sex. 年轻人在青春期对性逐渐产生较大兴趣. *
[attrib 作定语] a sex manual, ie giving information on sexual behaviour 性知识手册 *
a sex shop, ie selling pornography, devices to make sex more enjoyable, etc 性用品商店.

用法:
4 (idm 习语) the weaker sex => weak. sex 2
v [Tn] find out the sex(1) of (a creature) 鉴别（某生物）的性别:
sexing very young chicks 识别小雏鸡的性别.

• a kind of(one kind of)
• a lead(the lead)
• a little(only a little)
• a lot of(lots of)
• a lot(the lot)
• a man in the street(a woman of the streets, a woman on the streets)
• a man who(the man who)
• a mischief(the mischief)
• a most(the most)
• a need for(a need of)
• a number of(a quantity of)
• a number of(the number of)
• a one(a right one)
• a one(the one)
• a part of(part of)
• a people(the people)
• a rather long way(rather a long way)
• a rather(rather a(n))
• a reputation(the reputation)
• a second time(the second time)
• a sight to see(to see the sights)
• a sort of(of a sort)
• a sort of(sort of (a))
• a symbol for(a symbol of)
• a terror to(the terror of)