An urgent or crucial issue under heated discussion. For example, Real estate taxes are always a burning question for the town leaders. This term has exact equivalents in French (question brûlante) and German (brennende Frage). [Mid-1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.