Added 9 October 2026 seagrass /ˈsiˌɡɹæs/ noun Categories: AnimalsRare Words noun ! Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about seagrass at Wordnik → Where our words come from → Any of various grass-like marine plants that grow underwater in salt water. Related Words: eelgrassseaweedhalophilasargassumaquaticsea-weedgrasswrackturtlegrasspondweed Back to today's word