aluminum

noun

alu·​mi·​num ə-ˈlü-mə-nəm 

: a silver-white metallic chemical element with atomic number 13 that has good electrical and thermal conductivity, high reflectivity, and resistance to oxidation

—often used before another noun

aluminum foil

The sweet spot, the point in a bat where vibration supposedly is least, is said to be two times larger on an aluminum bat than on a wood one.

—Hank Hersch

Before he evacuated, Mr. Gonzales tied the boat down with four gigantic ropes and all the storm could do was knock it off the construction blocks. He slowly climbs a battered aluminum ladder propped up on the port side.

—Ken Wells

see Chemical Elements Table

Examples of aluminum in a Sentence

Recent Examples on the Web

Trump in April hit the UK with a 10% universal tariff and 25% tariffs that Trump imposed on foreign automobiles, steel and aluminum. —Rebecca Morin, USA Today, 9 May 2025

Trump has imposed steep tariffs on autos, steel, and aluminum since returning to office. —Amanda Castro hannah Parry, MSNBC Newsweek, 9 May 2025

In April, the Trump administration placed a 10% tax on imports from Britain, as well as 25% tariffs on autos, steel and aluminum, delivering a blow to the U.K., which exports a large percentage of British cars to the United States. —Aimee Picchi, CBS News, 8 May 2025

Notably, the steel and aluminum figure was not mentioned during Trump’s Oval Office announcement, though it is expected to be finalized soon. —Haisten Willis, The Washington Examiner, 8 May 2025

Word History

Etymology

alumine "alumina" (borrowed from French, borrowed from Latin alūmin-, alūmen alum entry 1) + -um (in the names of other metals, as platinum entry 1, tantalum)

First Known Use

1812, in the meaning defined above

Phrases Containing aluminum

• aluminum foil
• aluminum oxide
• aluminum sulfate

Rhymes for aluminum

• aluminium

Kids Definition

aluminum

noun

alu·​mi·​num ə-ˈlü-mə-nəm 

: a silver-white malleable light element that conducts electricity and heat well, is highly resistant to oxidation, and is the most abundant metal in the earth's crust see element

Medical Definition

aluminum

noun

alu·​mi·​num ə-ˈlü-mə-nəm 

: a silver-white malleable ductile light trivalent metallic chemical element with atomic number 13 that has good electrical and thermal conductivity, high reflectivity, and resistance to oxidation

—symbol Al see Chemical Elements Table