noun plural
: a dark-colored residue of former methods of petroleum distillation containing amorphous wax and formerly used in cracking and in waterproofing compositions
noun plural
: a dark-colored residue of former methods of petroleum distillation containing amorphous wax and formerly used in cracking and in waterproofing compositions
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012