| quaternary ammonium compound | |
| —n | |
| a type of ionic compound that can be regarded as derived from ammonium compounds by replacing the hydrogen atoms with organic groups | |
| a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question. |
| a fool or simpleton; ninny. |