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

The amount of aluminum in vaccines is much smaller than what kids already take in through eating, drinking and breathing, said Racine, of the American Academy of Pediatrics. — Brenda Goodman, CNN Money, 11 Aug. 2026

The aluminum bodywork was stretched four inches and lowered two inches, so as to further reduce drag. — Howard Walker, Robb Report, 10 Aug. 2026

The silicon-to-aluminum ratio tracked how big the diatom bloom was each year, while the manganese-to-iron ratio tracked how much oxygen the annual mixing drove into the water. — Jacek Krywko, ArsTechnica, 9 Aug. 2026

The Roam is built around an aluminum frame with a 100-mm hydraulic suspension fork and 60 mm of travel from a four-link rear setup. — New Atlas, 7 Aug. 2026

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