n.[C]

1. 记号，符号
2. 标志；招牌；标牌
   The sign says "Parking Forbidden".

   告示牌上写着“禁止停车”。

3. 手势；暗号；表示[+to-v][+that]
   I talked with him by signs.

   我和他用手势交谈。

4. 征兆；前兆[（+of）][+（that）]
   World trade is showing signs of revival.

   世界贸易正显示出重新活跃的征兆。

5. 【宗】神迹，显灵
6. 【医】体征
   Blood in phlegm can be a sign of lung cancer.

   痰中带血可能是肺癌的体征。

7. 【天】宫（十二宫）

vt.

1. 签（名）；写下
   He signed his name on the cheque.

   他在支票上签了名。

2. 签名于，签署
3. 签约雇用
4. 做手势（或其他动作）通知
   She signed the child to be quiet.

   她示意孩子安静下来。

5. 对……画十字
6. 预示
   All this signs rejuvenation of agriculture.

   所有这些都预示着农业将复苏。

vi.

1. 签字，署名
2. 签约受雇用[（+with）]
   He signed with the firm.

   他与那家公司签约。

3. 做手势示意
   She signed to us to stop talking.

   她做手势示意我们不要讲话。

n.

1. an object, quality, or event whose presence or occurrence indicates the probable presence, occurrence, or advent of something else.
   ▸Medicine  an indication of a disease detectable by a medical practitioner even if not apparent to the patient. Compare with symptom.
   ▸N. Amer. the trail of a wild animal.
2. a signal conveying information or an instruction.
   ▸a gesture used in sign language.
3. a public notice giving information or instructions in a written or symbolic form.
4. a symbol or word used to represent an operation, instruction, concept, or object in algebra, music, or other subjects.
5. Astrology  each of the twelve equal sections into which the zodiac is divided, named from the constellations formerly situated in each, and associated with successive periods of the year according to the position of the sun on the ecliptic.
6. Mathematics  the positiveness or negativeness of a quantity.

v.

1. write one's name on (something) for the purposes of identification or authorization.
   ▸write (one's name) for such a purpose.
2. (with reference to a sports player, musician, etc.) engage for or commit oneself to work by signing a contract.
3. use gestures to convey information or instructions.
   ▸communicate in sign language.
4. indicate with signposts or other markers.
5. mark or consecrate with the sign of the cross.