This has gotten lost in all the false meanings. A chip on his shoulder comes from the days when there was a formal declaration for a fight, punch-up etc. When a person disagreed strongly with someone over a personal belief, they would place a chip of wood on their shoulder and dare the other to knock it off. Once the other person did this signaled the beginning of the fight and thus punches were thrown. Examples of this can be seen in old British movies circa 1930-1950's.

We use this idiom to say that someone has a deeply held feeling or conviction about something (whether it annoys them or that they won't listen to any other opinion about it) and thus if you disagree then they will vehemently challenge you.
He has a real chip on his shoulder about his size, I had a chip on my shoulder about immigrants until I moved to another country.
by Speakada Lingo September 21, 2015
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This idiom simply means to harbour a grudge. It comes from the nineteenth century US practise of spoiling for a fight by carrying a chip of wood on one's shoulder, daring others to knock it off.
"Chip on my shoulder"--By: 50cent
Albulm---Get rich or die tryin'
Song tittle---Many men
by Unique April 8, 2004
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One who has something to prove.

The diversely sourced definitions of this phrase all have a common factor; it refers to someone whose behavior indicates that he/she has something to prove. Whether due to an inferiority complex, a strong passionate conviction for one's personal beliefs, a sense of being victimized or treated unfairly, or a resistance to heed advice from a more knowledgeable; one tends to display an air of hyped self-confidence and/or superiority or bravado.
"She's overly defensive because he's got a...
"See? I was right! I try to tell him; He should've listened to me! If it weren't for that...
"I think part of his drive for success and power can be attributed to that...

.....Chip on his shoulder."
by L!ghtBearer February 5, 2019
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A metaphor for being pissed off. Meaning one is angry or holding a grudge over something.
"Why are you so mad? You got a chip on your shoulder?"
by 3AGLE 3YE! September 30, 2015
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"Chip on his shoulder" commonly refers to someone who has a self-righteous feeling of inferiority or a grudge. An example would be someone always bringing up how they are or were disadvantaged in some way.
Person 1:"I was raised in a working class family with no luxuries"

Person 2:"But now you're a millionaire..."

Person 3:"Don't worry about him mate, he's just got a chip on his shoulder."
by ElectricFishy August 12, 2008
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The term means to interact in a provocative way, daring someone to resist you. When you are angry at someone, and instead of speaking about it, you do something to annoy them in hopes that they will argue with you, you’ve got a chip on your shoulder. Proactive Passive Aggression.
You've got a chip on your shoulder.
I cannot stand her she's got a chip on her shoulder.
by Roderick Sterling April 4, 2018
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To hold a grudge or grievance that is often brought forward to provoke a dispute
"Well you once said ..........."
"Dude remove the chip on your shoulder ....and shove it up your ass"
by Kristeng April 14, 2018
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