agar

noun

ˈä-gər 

1

: a gelatinous colloidal extract of a red alga (as of the genera Gelidium, Gracilaria, and Eucheuma) used especially in culture media or as a gelling and stabilizing agent in foods

2

: a culture medium containing agar

Examples of agar in a Sentence

Recent Examples on the Web

What to watch in the market this week Surprising discoveries Scientists depend on agar — a gelatin-like substance that comes from seaweed — to grow yeast. —Morgan Haefner, Quartz, 5 Aug. 2024

And yet here was agar, foiling day after day of experiments. —Bymolly Herring, science.org, 31 July 2024

Despite agar’s significance, few remember Hesse’s key role in microbiology history. —Corrado Nai, Smithsonian Magazine, 25 June 2024

Popular accounts of microbiology history sometimes attribute the first use of agar in laboratory settings to Koch. —Corrado Nai, Smithsonian Magazine, 25 June 2024

Word History

Etymology

short for Malay agar-agar, name for the red alga from which it is extracted

First Known Use

1885, in the meaning defined at sense 1

Phrases Containing agar

• agar-agar
• agar plate

Kids Definition

agar

noun

ˈäg-ər 

variants also agar-agar

ˈäg-ə-ˈräg-ər

1

: a jellylike substance obtained from a red alga and used especially in culture media or to give firmness to foods

2

: a culture medium containing agar

Medical Definition

agar

noun

ˈäg-ər 

1

: a gelatinous colloidal extract of a red alga (as of the genera Gelidium, Gracilaria, and Eucheuma) used especially in culture media or as a gelling and stabilizing agent in foods

2

: a culture medium containing agar