- technical a means of lighting or source of light〈技〉照明物, 发光源：
until 1880, oil was the only illuminant in use.
直到1880年, 油还是惟一使用的照明物。
- giving off light发光的, 照明的。
词源
mid 17th cent.: from Latin illuminant- 'illuminating', from the verb illuminare （see ILLUMINATE）.