bog down - 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.
Become stuck, be unable to progress, as in Their research bogged down because they lacked the laboratory expertise. This expression transfers sinking into the mud of a swamp to being hampered or halted. [First half of 1900s]