Verb
(chemistry, transitive) To add one or more protons to (a molecule, ion or radical).
protonate the carbonyl group
(chemistry, intransitive) To acquire an additional proton.
Source: en.wiktionary.orgAs a bicyclic, heterocyclic purine derivative, uric acid does not protonate as an oxygen (−OH) like carboxylic acids do. Source: Internet
Strong acids protonate the oxygen to give "onium ions". Source: Internet
Superacids can permanently protonate water to give ionic, crystalline hydronium "salts". Source: Internet