meter is running, the - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Costs or other consequences are accumulating, as in We'd better come to a decision soon, for the meter is running. This metaphoric expression alludes to the fare mounting up on a taxi meter. [Late 1900s]