When someone has a “beef” with someone else, it means a “grudge” or a “complaint.” The word “beef” does not mean “meat,” but the confusion leads to some humor.
 
“Is a disagreement between two vegans still called a beef?” was posted on Twitter by Not Interested on August 24, 2010. “Is a rivalry between two vegans still considered a beef?” was posted on Twitter by Paul El Zapatero on October 28, 2010. “My husband text me: ‘Is an argument between two vegans still considered a ‘beef?’’” was posted on Twitter by MW on November 23, 2010. “If two vegans have a fight, is it still called a beef? #fb” was posted on Twitter by Michael Nelson on December 1, 2010. “If two vegans fight, is it still considered beef?” was posted on Twitter by Kevin O’Leary on December 9, 2010.
   
“When two vegetarians are arguing, is it still considered beef?” and “If two vegans have an argument, is it still called a beef? Or is it a quornfrontation?” are related sayings.
   
     
Wiktionary: beef 
Noun
beef (plural beef or beefs or beeves)
(...)
4. (slang, countable or uncountable, plural: beefs) a grudge (+ with)
   
Twitter
Not Interested
@Elvancho
Is a disagreement between two vegans still called a beef?
10:57 AM · Aug 24, 2010·Echofon
 
Twitter
Paul El Zapatero
@2PapiPaul
Is a rivalry between two vegans still considered a beef?
7:07 PM · Oct 28, 2010·TweetDeck
     
Twitter
MW
@13_Frede
My husband text me: “Is an argument between two vegans still considered a ‘beef?’”
3:13 PM · Nov 23, 2010·Twitter SMS
   
Twitter
Michael Nelson
@michaelwnelson
If two vegans have a fight, is it still called a beef? #fb
11:54 AM · Dec 1, 2010·Twitter for iPhone
   
Twitter
Kevin O’Leary
@ThatIrishDude
I figured @LexxZee would know the answer to this. If two vegans fight, is it still considered beef?
6:15 PM · Dec 9, 2010·TweetDeck
 
Twitter
Elisabeth O’Rourke
@elisabethorourk
If two vegans get into a rivalry, is it still called a beef?
10:57 PM · Jan 19, 2011·Twitter Web Client
 
Twitter
Devin Reese
@SugaFreeTTG
“If two vegans get into an argument, can they have beef?” ahahahaa
4:48 PM · Mar 10, 2011·Twitter SMS
       
Twitter
Miles
@PunkSoda
Is a rivalry between 2 vegans still called a beef?
9:03 PM · Mar 22, 2011·Twitter Web Client
 
Twitter
elyssa
@swandiive
If two vegans get into a fight is it still called a beef ?
9:58 PM · May 18, 2011·Twitter for BlackBerry®
 
Twitter
Marc Lavarin@marclavarin·Nov 16, 2011
Replying to @Prettyailes
RT @Prettyailes Is an argument between two vegans still called a beef?!? #cornytwit// ONLY YOU SYLVIE LOL
           
Reddit—Showerthoughts
Posted by u/youluckypeople September 19, 2014
If two vegans are arguing, Is it still considered “beef” ?
   
Reddit—Dadjokes
Posted by u/jinnyjuice September 19, 2014
If two vegans are arguing, is it still considered beef?
 
Reddit—Showerthoughts 
Posted by u/zetsui September 26, 2014
If two vegans get into a fight ...do they have beef with each other?
 
Reddit—Jokes
Posted by u/Sparkatiz October 20, 2014
If two vegans are arguing.
Is it still considered beef?
   
Reddit—Jokes
Posted by u/Awonymous December 19, 2015
If two vegans have an argument…
is it still considered beef?
   
Reddit—3amjokes
Posted by u/spillitout123 January 20, 2017
If two vegans are fighting
Is it still called beef?
 
Reddit—Dadjokes
Posted by u/sault9 April 1, 2021
If two vegans get in a fight…
... is it still considered a beef?