noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   Any oxide containing three oxygen atoms for every two atoms of another element.

Etymology

From sesqui- (“one and a half, a ratio of three to two”) + oxide.

Related phrases

antimony sesquioxidearsenic sesquioxidechromium sesquioxideholmium sesquioxide

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.