Irish moss

noun

1

: the dried and bleached parts of a red alga (especially Chondrus crispus) used as an agent for thickening or emulsifying or as a demulcent and as a source of carrageenan

2

: a red alga that is a source of Irish moss

called also carrageen

Examples of Irish moss in a Sentence

Recent Examples on the Web

Symbiotica’s high-dose liposomal supplements — vitamin C, magnesium and Irish moss sachets — sit alongside Neuromints adaptogen mints and H2 hydrogen tablets. — Ritu Upadhyay, Footwear News, 21 Aug. 2026

As a perennial, Irish moss will come back every year as long as it is provided with adequate care. — Natalia Gonzalez Blanco Serrano, The Spruce, 5 Apr. 2026

Infused with amla oil, Irish moss, and agave nectar, the clean and creamy formula helps soften dense curls while keeping them flexible and manageable during styling. — Conçetta Ciarlo, Vogue, 10 Mar. 2026

Irish moss is evergreen and tolerates moderate to heavy foot traffic, making a lovely lawn alternative. — Kim Toscano, Southern Living, 19 Aug. 2025

Word History

First Known Use

1837, in the meaning defined at sense 1

Rhymes for Irish moss

• albatross
• applesauce
• barabbas
• helios
• kshatriyas
• menelaus
• across
• backcross
• crisscross
• lacrosse
• recross
• tomas

Kids Definition

Irish moss

noun

: either of two red algae

also : these algae when dried and bleached for use especially as thickeners or soothing agents (as in food or lotions)

Medical Definition

Irish moss

noun

ˌī(ə)r-ish-ˈmȯs 

1

: the dried and bleached plants of a red alga (especially Chondrus crispus) that are used as an agent for thickening or emulsifying or as a demulcent (as in cookery or pharmacy)

called also chondrus

2

: a red alga (especially Chondrus crispus) that is a source of Irish moss

called also carrageen