oxygen acid oxygen-acetylene welding • oxygen-hydrogen welding · · · Info · Definitions · Synonyms · Characters · · oxygen acid · · Text Common · · Latin · · Scripts 11 · · Length Definitions · · · (noun) any acid that contains oxygen. Synonyms: oxyacid. · · Noun Definition 1 Synonyms · · · oxygen · · Synonym 1 o · · Synonym 2 atomic number 8 · · Synonym 3 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 g latin small letter g U+0067 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F x latin small letter x U+0078 y latin small letter y U+0079