- to repulse; repel
- to struggle to avoid or repressto fight off a cold
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Idioms and Phrases with fight off
Defend against, drive back, as in I've been fighting off a cold all week. This figurative use of the term, originally meaning “to repel an enemy” dates from the early 1800s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.