Definition

1. Noun:
   • A red-coloured lamp: "red lamp" refers to a lamp that emits red light, often used as a signal or indicator.
   • A sign for a pharmacy or doctor's surgery: Historically, a red lamp hung outside a pharmacy or doctor's house to indicate that the premises were open or that a doctor was on call.
   • A traffic signal: In some contexts, "red lamp" can mean a red traffic light, instructing vehicles to stop.
   • A warning signal: A red lamp can be used to indicate danger or an emergency situation.
   • Slang for a brothel: In informal usage, "red lamp" can refer to a house of prostitution, derived from the red lamps traditionally placed outside such establishments.

Usage Examples

• As a pharmacy sign:

  • The doctor hung a red lamp outside his clinic to show he was available for emergencies. (A red-coloured lamp used as a sign for medical services.)

• As a traffic signal:

  • The train driver saw the red lamp and immediately applied the brakes. (A red light used as a stop signal.)

• As a warning signal:

  • The red lamp on the control panel flashed, indicating a system failure. (A red light used to alert of a problem.)

• As slang for a brothel:

  • The old part of town was known for its red lamps and other illicit businesses. (Informal reference to houses of prostitution.)

Advanced Usage

• "to see a red lamp": to encounter a stop signal or a warning.

  • The engineer saw a red lamp ahead and slowed the train. (He observed a stop signal.)

• "under the red lamp": in the context of a brothel or red-light district.

  • The novel described life under the red lamp in Victorian London. (Life in the prostitution district.)

Variants and Related Words

• Red-light district (n): an area of a city known for its brothels and sex-related businesses.

  • Tourists often visit the red-light district out of curiosity. (A neighbourhood associated with prostitution.)

• Red lamp as a compound noun: often written as two separate words, but can be hyphenated as "red-lamp" when used attributively.

  • The red-lamp shop was closed after the police raid. (A shop associated with red lamps, likely a brothel.)

Synonyms

• Stop light: a red traffic signal.
• Warning light: a red light used to indicate danger.
• Brothel sign: a colloquial term for a red lamp used in prostitution contexts.

Related Idioms

• "to fly the red lamp": to operate a brothel (archaic slang).

  • The old woman was accused of flying the red lamp in her house. (She was running a brothel.)

• "red lamp fever": a humorous or informal term for excitement or danger associated with red-light districts.

  • The tourists caught red lamp fever and spent the night exploring the district. (They became fascinated by the area.)