“Corn teen” (or “corn-teen” or “cornteen”) means “quarantine” and has nothing to do with corn or a teenager.  The jocular “cornteen” has been printed on many images and became popular during the 2019–20 coronavirus pandemic.
   
“Watching corn teen!  Haha (Quarantine)” was posted on Twitter by Collin Chong on August 5, 2011. “@shayybuttababy needs to be cornteen ! making everyone sick !” was posted on Twitter by Sueie on November 15, 2011.
     
“Cornteen” was entered in the Urban Dictionary on March 27, 2020.
   
       
Wikipedia: 2019-20 coronavirus outbreak
The 2019–20 coronavirus pandemic is an ongoing global pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The outbreak was first identified in Wuhan, Hubei, China, in December 2019, and was recognised as a pandemic by the World Health Organization (WHO) on 11 March 2020.
           
Twitter
Collin Chong
@ayocollin
Watching corn teen!  Haha (Quarantine)
3:54 AM · Aug 5, 2011·Twitter SMS
   
Twitter
Sueie
@shayydeeee
!!!! Lmaoooo RT @gabby_lotsofass: @shayybuttababy needs to be cornteen ! making everyone sick !
6:47 PM · Nov 15, 2011·Echofon
 
Twitter
Dan of the Dead
@danr1231
CORN-TEEN. #Quarantine
10:57 PM · Jul 17, 2012·Twitter for iPhone
 
Twitter
Niyah Wu
@niyahdwyer
My sister spelt “quarantine” like “cornteen”
7:54 PM · Apr 17, 2015·Twitter for iPhone
 
Twitter
@Alex_Shepy
@AlexShepy
Replying to @AshSerigala
The U.S. isn’t doing shit about the virus so there maybe a con but I guess if it gets bad enough the U.S. military will put up cornteen check points every where
1:15 AM · Feb 26, 2020·Twitter for Android
   
Twitter
CherryHerb
@cherry_coloured
Replying to @Gaelforced @WhiskeyAngel101 and @slimseanie
#CornTeen
2:48 PM · Mar 12, 2020·Twitter for iPhone
   
Twitter
Tove
@tcc300892
Americans: “Cornteen”.
5:57 PM · Mar 15, 2020·Twitter for Android
   
Twitter
Dina
@dna_abu
Day #1 of cornteen
GIF
6:12 PM · Mar 16, 2020·Twitter for iPhone
   
Twitter
Cocolicko
@smilee_itsMeesh
I seen somebody spell quarantine as cornteen and I been hollering err since. Like we literally take everything as a joke
10:02 PM · Mar 16, 2020·Twitter for iPhone
 
Urban Dictionary
Cornteen
Internet slang for “quarantine”, originating from the many times people misspelled that word on social media during the COVID-19 or coronavirus crisis. Often used in posts expressing boredom or frustration related to self-quarantine or ‘social distancing’ measures.
 
Sometimes also (mis)spelled ‘corn teen’, ‘corn and teen’, ‘corn in teen’ or ‘corn of teen’.
(...)
by 2020Dutchman March 27, 2020
 
(Trademark)
Word Mark YINZ ARE TOO CLOSE MOVE BACK, JAGOFF CORN-TEEN N’@
Goods and Services IC 025. US 022 039. G & S: Hats; Shirts and short-sleeved shirts; Baseball caps and hats; Night shirts; Sweat shirts; T-shirts; Tee shirts
Standard Characters Claimed
Mark Drawing Code (4) STANDARD CHARACTER MARK
Serial Number 88874365
Filing Date April 16, 2020
Current Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) Topolosky, Gary P. INDIVIDUAL UNITED STATES 4031 Brownsville Road Pittsburgh PENNSYLVANIA 15227
Attorney of Record Gary P. Topolosky
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator LIVE