Someone with an extremely short memory, or one who is extremely absentminded.

Derives from the evolutionary defense mechanism of the American Goldfish in order to stave off insanity due to boredom: "wow look at that pretty plastic tree"... "wow look at that pretty plastic tree"... "wow look at that pretty plastic tree"
"Damn...That Sue never learns... She just does the same dumb shit over and over again like a goldfish."
by SueLowe October 10, 2005
1. A popular pet often kept in bowls (which they shouldn't, that's bad for them) and often thought of as having a 3 second memory, though this is a myth, because in reality goldfish have a longer memory than you do.

2. The snack that smiles back.

3. People that have a super short memory, originating from the myth that goldfish have a 3 second memory (which they don't)
1:

SMART son:"Mom, I found a goldfish!"
Mom: "Ok, keep it in your bowl"
SMART son: "FUCK YOU YOU DON'T KNOW SHIT ABOUT TAKING CARE OF GOLDFISH"

2:

"I had some goldfish yesterday. I wonder why it was smiling at me even though it was gonna die and get digested and turn into shit."

3:

SMART daughter: "Dad, look at that goldfish!"
Dad: "Oh, that's a person, not a goldfish!"
SMART daughter: "DUMBASS I WAS THINKING OF THE PERSON "
by Corey the best Definer July 20, 2016
A pet that doesn't do anything.
My goldfish was named Snappy.
by Angelacia March 8, 2008
Fish-shaped crackers that are baked, not fried.
Dat bitch's gonna pop yo punk ass because yo ate dems GoldFish, yo .
by ALLAH January 13, 2004
A girl whose only purpose is to look pretty. A goldfish is promiscuous and capable of having 100s of children in her lifetime all while ruining entire ecosystems. A goldfish does not contribute anything to society other than it's decorative outer beauty. Also know as a golddigger.
Brad: Yo I met this girl name Rachel on tinder.
David: Yo, don't talk to her she's a goldfish!
by DiscoCigs December 15, 2016
1. A cheesy cracker shaped like a fish. It tends to smile back.
2. A person who is very forgetful or seems to have no memory at all.
3. A person who wears glasses that make their eyes look huge. Much like a goldfish's.
1. Michael: What are those cheesy snacks that always smile?
Brian: You mean goldfish?
Michael: Yeah!

2. Amy: Did you finish your homework last night?
Sarah: ...I don't know...What'd you ask me?

3. Nina: You see Rachel's glasses?
Emily: Yeah, now she's a goldfish.
by TKumi March 26, 2008