opal

Fetched 2026-10-26 (cache).

Datamuse reports no synonyms or antonyms for this word.

Noun

1. {{senseid|en|Q171058}} {{lb|en|mineral}} A mineral consisting, like [[quartz]], of [[silica]], but inferior to quartz in hardness and [[specific gravity]], of the [[chemical formula]] [[silicon|Si]][[oxygen|O]]₂'''·'''n[[water|H₂O]].
2. The colour of opal: any [[shade]] of [[blue]] with bright [[fleck]]s of other colours, such as white, yellow, and red.
3. {{lb|en|biology|genetics|biochemistry}} A colloquial name used in [[molecular biology]] referring to a particular [[stop codon]] sequence, "UGA."
4. Any of various [[lycaenid]] butterflies of the [[genus]] {{taxlink|Nesolycaena|genus}}.

Proper noun

1. {{given name|en|unisex|from=English}} from the precious stone, invented in the nineteenth century.
2. {{lb|en|Australia}} A type of [[petrol]] made by {{w|British Petroleum}} designed to be unable to be used for [[petrol sniffing]].<ref>[https://web.archive.org/web/20060910003444/http://www.bp.com/sectiongenericarticle.do?categoryId=9008933&contentId=7016884 BP article on Opal].</ref>{{defdate|Developed 2005.}}
3. {{place|en|hamlet|p/Alberta|c/Canada}}.
4. {{place|en|census-designated place|s/Virginia}}.
5. {{place|en|town|s/Wyoming}}.

Source: Wiktionary · CC BY-SA 4.0 (Wiktionary dump) · cached copy, not a rewrite.