名词

1. (刀、剑的)鞘，套
A sheath is a covering for the blade of a knife.

2. 保险套;避孕套
A sheath is a rubber covering for a man's penis and is used during sex as a contraceptive or as a protection against disease.

1. a dress suitable for formal occasions

Synonym: cocktail dress

2. a protective covering (as for a knife or sword)

3. an enveloping structure or covering enclosing an animal or plant organ or part

Synonym: case