n. Any of several dimethyl derivatives of pyridine, but especially 2,6-dimethyl pyridine that occurs in coal tar
the GNU version of the Collaborative International Dictionary of English
n. Any one of several metameric alkaloids, C5H3N.(CH3)2, of the pyridine series, obtained from bone oil as liquids, and having peculiar pungent odors. These alkaloids are also called respectively dimethyl pyridine, ethyl pyridine, etc.
The Century Dictionary and Cyclopedia
n. The collective name of the various isomeric dimethylpyridines, (CH3)2C5H3N. They are present in coal-tar oil and in animal-and bone-oil, and resemble pyridine in general properties.
Word Usage
"When distilled with potassium hydrate it yields quinoline, lutidine, and two isomeric collidines."