Green’s Dictionary of Slang

chubby n.

1. a short, squat umbrella.

in W.E. Collinson Contemp. Eng.

2. (US) a mink coat.

[US]N. Algren ‘Watch Out for Daddy’ in Entrapment (2009) 138: All she had in mind was showing the chubby off in front of Enright’s other hookers [...] ‘Little baby, you don’t need a furpiece to walk half a city block’. [ibid.] 139: All I want is to wear my very own mink chubby to work.

3. (also chub) an erection [play on fat n. (4)].

chat.thevalkyrie.com 22 May 🌐 Scooby – Did you have a chubby through the whole match?
OnLine Dict. of Playground Sl. 🌐 chubby, chub n. a semi-erection partial-hardon.
[US]J. Ellroy ‘Hollywood Fuck Pad’ in Destination: Morgue! (2004) 235: I awoke with a chart-busting chubby.
[US]Slate 8 Feb. 🌐 I got a quarter chub just looking at the map.
[Aus]D. Whish-Wilson Old Scores [ebook] Their chubbies hadn’t faded, which was a good thing. In all his years, Swann had never seen a man with a stiffie throw a punch.
[US]T. Pluck Boy from County Hell 105: Timmy had gotten a chubby when the big Black bastard had hefted him.

In compounds

chubby-chaser (n.)

a man who prefers (unfashionably) plump or fat women or, if gay, men.

[US]‘Bubbles & Baubles’ in Screw 8 Dec. 27: Man of 30 and 300 lbs with versatility wants to make connections with chubby chasers club. Only discreet replies will be acklowedged. P.O. Box 339 [etc].
T. Anicar Secret Sex: Male Erotic Fantasies n.p.: Fat women. I am a ‘chubby chaser’.
[US]Maledicta IV:2 (Winter) 227: Dora (Dumb Dora) and Dumbo [...] are heard and so is Bertha for a big one (elephant or chubette, delight of the chubby-chasers).
[US]Jaffe Cohen & Bob Smith ‘To Think That I Saw Him On Christopher Street’ 🎵 First there were ‘chubbies’ the guys who were fat / Balancing ‘chasers’ who like them like that.
[SA]K. Cage Gayle 62/1: chubby chaser n. a man who likes overweight men [American Gayspeak].
[US]J. Ellroy ‘Hollywood Fuck Pad’ in Destination: Morgue! (2004) 231: Chuckie’s a chubby-chaser that likes fat chicks.
[US]J. Ellroy Widespread Panic 6: He was the King of the Chubby Chasers. He longed for it laaarrrge.
chubbyfat (adj.)

(US black) very fat, obese.

[US]C. Major Juba to Jive 96: Chubbyfat adj. (1940s–1950s) to describe extreme obesity.

In phrases

give someone a chubby (v.)

(UK juv.) to pinch and twist someone’s nipple, as an aggressive greeting or a punishment.

OnLine Dict. of Playground Sl. 🌐 chubby (to give a... ) v. To pinch and twist someones nipple (A chubby nipple). Can be used as a threat, punishment or greeting in some cases.