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

In 2018, Trump imposed a 25 percent tariff on steel and a ten percent tariff on aluminum. —Michael B. G. Froman, Foreign Affairs, 11 Aug. 2025

The aluminum Orico MiniMate also functions as an 8-in-1 hub and comes with a 5Gbps USB-A port, three USB 2.0 480Mbps ports, a 3.5mm headphone jack, a 3.5mm microphone input, plus slots for SD and MicroSD memory cards. —Mark Sparrow, Forbes.com, 10 Aug. 2025

Though similarly named, the current model isn't quite a convertible version of the ThinkPad X1 Carbon Gen 13, opting for aluminum instead of carbon fiber and magnesium, and weighing significantly more (2.97 pounds versus the Carbon’s 2.17 pounds). —Charles Jefferies, PC Magazine, 10 Aug. 2025

Lavery anticipates aluminum tariffs will be manageable for Monster, estimating that the metal is about 10% of its cost of goods. —Sean Conlon,lisa Kailai Han, CNBC, 7 Aug. 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