Definition

1. Adjective:
   • Not containing tetraethyl lead: Specifically describes gasoline or fuel that has been manufactured without the addition of the anti-knock agent tetraethyl lead.
   • Lead-free: A more general term indicating the absence of lead, often used interchangeably with "unleaded" in the context of fuel.

Usage

• The adjective "nonleaded" is used almost exclusively to describe fuel, particularly gasoline. It specifies the type of fuel suitable for vehicles with engines designed to run without leaded gasoline.
• It is typically used attributively (before a noun) or predictively (after a linking verb like "is" or "was").

Examples

• Attributive use:
  • Most modern cars require nonleaded gasoline.
  • The station only sells nonleaded fuel.
• Predictive use:
  • Is this gasoline nonleaded?
  • The fuel we use is strictly nonleaded.

Advanced Usage

• Technical/Environmental Context: The term is used in technical specifications, environmental regulations, and automotive manuals to denote fuel that meets specific emission and engine compatibility standards.
  • The new environmental law mandates that all gasoline sold must be nonleaded.

Variants and Related Words

• Unleaded (adj.): The more common and nearly synonymous term for gasoline not containing tetraethyl lead.
  • Unleaded gasoline is the standard in many countries.
• Lead-free (adj.): A broader term that can apply to other substances like paint, pipes, or solder, not just fuel.
  • We installed lead-free pipes in the house.

Synonyms

• Unleaded: (For fuel) Not containing tetraethyl lead.
• Lead-free: Free from lead content.

Antonyms

• Leaded: (Of gasoline) Containing tetraethyl lead.
  • Leaded gasoline is now banned in most regions.

Adjective

1. (of gasoline) not containing tetraethyl lead
   • lead-free gasoline