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

Emptied and rinsed aluminum cans, plastic bottles, and cardboard boxes from the week’s meals usually pile up quickly, but what about the pizza box from last night’s dinner or the takeout containers from lunch? —Karen Brewer Grossman, Southern Living, 15 Feb. 2026

All the wraparound glass makes the R33 feel like a fishbowl, albeit one trimmed in buttery leather and brushed aluminum. —Tim Pitt, Robb Report, 14 Feb. 2026

It was opened as a hotel in September 2025, and while the classified documents have been removed, a vestige of America’s prowess remains in the form of a golden eagle sculpture crafted from aluminum from B-52 fighter jets. —Sofia Celeste, Footwear News, 14 Feb. 2026

The automaker absorbed roughly $2 billion in losses tied to fires at a Novelis aluminum supplier plant in New York. —Benzinga, Freep.com, 14 Feb. 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