“Why do they call guns arms and arms guns?”

A gun is a “firearm,” or “arms” in the plural. “Guns” is slang for “biceps.” A popular question is:
 
“Why do they call guns arms and arms guns?”
 
“Why do people call guns arms (‘I’m loading up on arms’ ) and arms guns (‘guys, check out my guns!’ )?” was posted on Twitter on February 20, 2009. “We call our arms guns and our guns arms” was posted on Reddit—Shower Thoughts on February 3, 2015.
     
       
Twitter
Kelvin Kao‏
@kelvinkao
Why do people call guns arms (“I’m loading up on arms”) and arms guns (“guys, check out my guns!”)?
7:51 PM - 20 Feb 2009
   
Twitter
Carter Cross‏
@CarterCCross
Why do we call our arms “guns” and our guns “arms”?
9:32 PM - 28 Jun 2011
 
Twitter
Jennifer Hoffman‏
@jen_thehoff
I just don’t get why guys call their arms guns and their guns arms…
1:37 AM - 12 Feb 2012
 
Twitter
maria kashubin‏
@mmkashubin
Ever wonder why we call our arms guns, and our guns arms? Mind=BLOWN!!
5:05 PM - 22 Aug 2012
 
Twitter
Nicki Hurley‏
@milkpoe6
Why are our arms called guns and guns called arms? #TweetLikeJadenSmith
11:11 PM - 14 Jul 2014
 
Reddit—Shower Thoughts
We call our arms guns and our guns arms.
submitted February 3, 2015 by TheWestPointer
 
Reddit—Shower Thoughts
Why are guns called arms and arms called guns?
submitted November 2, 2015 by blisteringchristmas
 
Twitter
Jillian‏
@jilliancyork
why do we call guns arms and arms guns?
5:49 AM - 13 Mar 2017
 
Reddit—Oneliners
Why do they call guns arms and arms guns? (self.oneliners)
submitted September 14, 2017 by xMikee