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

Their propellants are a mixture of fuel and oxidizer, with metallic powders such as aluminum often serving as the fuel. —Robert Birsel, MSNBC Newsweek, 9 Sep. 2025

Tidy up your plastic, glass, aluminum, or resin patio sets with a good spritz of Windex. —Melissa Locker, Southern Living, 8 Sep. 2025

The robust steel hull is contrasted by a lightweight aluminum superstructure that is purposely minimal in design to maximise the views from indoors. —Rachel Cormack, Robb Report, 8 Sep. 2025

This clean-ingredient, aluminum-free roll-on is gentle on your delicate underarm skin. —Kristen Philipkoski, Forbes.com, 8 Sep. 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