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

But the administration may be open to adding a blanket tariff like the steel and aluminum levies to bikes, especially now that the Supreme Court has struck down many of its other import taxes. —Scott Horsley, NPR, 29 Mar. 2026

And then, of course, there’s Rimowa, the hyper-popular German maker known for its rolling aluminum trunks—and ironclad lifetime guarantee. —Justin Fenner, Robb Report, 28 Mar. 2026

Many of his parts are made of aluminum sourced outside the country. —Max Scheinblum, Denver Post, 27 Mar. 2026

The Strait of Hormuz is a critical transit route not just for oil, but also liquefied natural gas, fertilizers, helium and aluminum – all of which Russia produces in vast quantities. —Hanna Ziady, CNN Money, 27 Mar. 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