[as modifier] Of or denoting the radical —OH, present in alcohols and many other organic compounds.‘a hydroxyl group’
- ‘Water always contains small quantities of two ions, hydronium ions and hydroxyl ions (OH -).’
- ‘At present the evidence for hydroxyl radicals being mutagenic is limited.’
- ‘In the atmosphere the hydroxyl radicals oxidise nitrates to form ozone.’
- ‘Phenols are a subgroup of alcohol in which the hydroxyl groups are attached directly to the carbon atoms of a ring structure.’
- ‘The carbonyl group can be broken down by the action of hydrogen cyanide; a hydroxyl group and a nitrile group are formed in this reaction.’
Mid 19th century: from a blend of hydrogen and oxygen, + -yl.
We take a look at several popular, though confusing, punctuation marks.