Definition

1. Verb (transitive):

   • To cause a person or animal to gain weight, typically by providing more or richer food, often with the intention of preparing them for slaughter or sale.
   • To make something fuller, larger, or more substantial.

2. Verb (intransitive):

   • To gain weight oneself.

Usage

• As a transitive verb, "fatten up" takes a direct object (the person or animal being fed).
• It is a separable phrasal verb. The object can often come between "fatten" and "up" (e.g., ).
• It is commonly used in agricultural contexts but can be applied informally to people.

Examples

• Transitive use:
  • The farmers are trying to fatten up the pigs before the fair.
  • She's been fattening her son up with home-cooked meals since he returned from college.
• Intransitive use:
  • I need to fatten up a bit before the winter.
• Figurative use (making something more substantial):
  • He added some anecdotes to fatten up his presentation.

Advanced Usage

• "fatten someone/something up for something": This structure implies a specific purpose for the weight gain.
  • They are fattening the turkey up for Thanksgiving.
  • (Figurative) The company was fattened up for a takeover.

Variants and Related Words

• Fatten (verb): The base verb, often used interchangeably with "fatten up," though "fatten up" can sound more informal or complete.
• Plump up (verb): A close synonym, often used for making something softer and rounder (e.g., ).
• Put on weight (verb phrase): A more neutral phrase for gaining weight.

Synonyms

• Plump up
• Feed up
• Build up (in the context of making something more substantial)

Related Phrasal Verbs

• Beef up: To make something stronger or more substantial, often used for non-living things like security, arguments, or text.
  • We need to beef up the security system.
• Bulk up: To gain muscle mass or size, typically through exercise and diet.
  • He's been lifting weights to bulk up.

Idioms and Related Expressions

• "Fatten the calf": An idiom derived from the biblical parable of the prodigal son, meaning to prepare a lavish celebration for someone's return.
  • When their daughter announced she was coming home, they began to fatten the calf.
• "Fatten one's wallet/purse": To make oneself richer.
  • The corrupt official was more interested in fattening his wallet than serving the public.

Verb

1. make fat or plump
   • We will plump out that poor starving child