English Reference
adjective · noun

fatty

adj. · n.
US /ˈfæti/ UK /fˈæti/ fat·ty

  1. 01 B1 Intermediate

    adj.containing a lot of fat or oil.

    adj.containing, composed of, or consisting of a high proportion of fat.

    Simple

    You should avoid eating too many fatty foods like chips and burgers.

    In context

    The chef recommended a sharp citrus dressing to balance the fatty texture of the roasted duck breast.

    leanlow fat
  2. 02 C2 Proficiency InformalSlangVulgar

    n.a very rude and unkind name for someone who is fat.

    n.a derogatory and offensive term for an obese person.

    Simple

    The bullies at school used to call him 'fatty' during gym class.

    In context

    The use of such derogatory epithets as 'fatty' in the workplace is often grounds for immediate disciplinary action regarding harassment.

    Usage

    Used as a direct insult or a cruel nickname.

    Teacher's tip

    This term is highly offensive and should be avoided; it is included here so learners recognize it as a hostile insult rather than a neutral descriptor.

  3. 03 C2 Proficiency Slang

    n.a thick or large cigarette containing marijuana.

    n.a large or thick marijuana cigarette, often referred to as a blunt.

    Simple

    In the movie, the characters were sitting on the porch rolling a fatty.

    In context

    The lyrics of the song contain several references to rolling a fatty, reflecting the counter-culture themes of the era.

Suppose I’m interested in helping my pregnant sister understand whether taking fish oil, which contain omega-3 fatty acids – specifically DHA – during pregnancy will help lower her chances of having a preterm birth.

The Conversation· 4 Aug 2026

Some became giants themselves—prehistoric forms more than 60 feet in length—and all developed insulating layers of fatty blubber to help regulate their body temperature in the sea.

Smithsonian Magazine· 27 Jul 2026

Etymology 1

From Middle English fatty, equivalent to fat + -y. Cognate with Saterland Frisian fattig (“fatty”), Dutch vettig (“fatty, greasy”), German Low German fettig (“fatty”), German fettig (“fatty”).

Etymology 2

From fat + -y (diminutive suffix).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Middle English fatty
Level C2 · Proficiency
Frequency Frequent
Updated