Function: noun
Date: 1842
: a system of cooperation among active antislavery people in the U.S. before 1863 by which fugitive slaves were secretly helped to reach the North or Canada ― called also Underground Railway
UNDERGROUND RAILROAD
Meaning of UNDERGROUND RAILROAD in English
Merriam Webster Collegiate English Dictionary. Merriam Webster - Энциклопедический словарь английского языка. 2012