Citations:thickened


 * 1818 — Mary Shelley. Frankenstein.
 * As I still pursued my journey to the northward, the snows thickened and the cold increased in a degree almost too severe to support.


 * 1843 — Charles Dickens. A Christmas Carol.
 * Meanwhile the fog and darkness thickened so, that people ran about with flaring links, proffering their services to go before horses in carriages, and conduct them on their way.