- The univalent group, −COOH, the functional group characteristic of all organic acids.
- A hypothetical organic radical having the formula COOH.
- The complex radical, CO.OH, regarded as the essential and characteristic constituent which all oxygen acids of carbon (as formic, acetic, benzoic acids, etc.) have in common; -- called also <altname>oxatyl</altname>.
- A <xref>univalent</xref> <xref>functional group</xref> consisting of a <xref>carbonyl</xref> and a <xref>hydroxyl</xref> functional group (-<xref>CO.OH</xref>); characteristic of <xref>carboxylic acids</xref>.
- relating to or containing the carboxyl group or carboxyl radical
- the univalent radical -COOH; present in and characteristic of organic acids