Definition

1. Adjective:
   • Similar in function or role but not in origin or structure: Used to describe things that perform comparable functions or have similar relationships, despite having different evolutionary origins, historical developments, or fundamental natures.
   • Comparable in certain respects, allowing for a useful analogy: Used to indicate that two things are sufficiently similar in specific aspects to be compared, even if they are dissimilar in other ways.

Usage and Examples

• Describing functional similarity despite different origins:

  • The wings of a bird and the wings of an insect are analogous structures; both are used for flight but evolved independently.
  • A book's index and a website's search bar serve analogous purposes in helping users find information.

• Describing comparable qualities or relationships:

  • The relationship between a teacher and a student is analogous to that between a coach and an athlete.
  • In this economic model, consumer demand is analogous to water pressure in a pipe system.

Advanced Usage

• "To be analogous to": This is the most common construction for drawing a direct comparison.
  • The human heart is often said to be analogous to a pump.
• In formal/logical contexts: Used to describe a correspondence between two ratios or relationships (forming an analogy: A is to B as C is to D).
  • In the analogy "pen : write :: knife : cut," the relationships between the pairs are analogous.

Variants and Related Words

• Analogy (noun): A comparison between two things, typically for the purpose of explanation or clarification.
  • He explained the complex theory using a simple analogy.
• Analog (noun/adjective): As a noun, something that is analogous or comparable. As an adjective, relating to or using signals or information represented by a continuously variable physical quantity (contrasted with digital).
  • The vinyl record is an analog format for sound storage.

Synonyms

• Comparable: Able to be likened to another; similar.
• Similar: Having a resemblance in appearance, character, or quantity.
• Corresponding: Having a similar relationship or function; equivalent.
• Alike: Similar to each other.

Antonyms

• Dissimilar: Not alike; different.
• Homologous: Similar in position, structure, and evolutionary origin but not necessarily in function (a key biological distinction from 'analogous').
• Unrelated: Having no connection or relationship.

Common Phrases and Constructions

• Draw an analogy between X and Y: To explicitly point out how X and Y are analogous.
  • The author draws an analogy between the growth of a city and the growth of a living organism.
• By analogy (with): Using a comparable case as a basis for reasoning or explanation.
  • We can understand this new concept by analogy with a more familiar one.

Adjective

1. corresponding in function but not in evolutionary origin
   • the wings of a bee and those of a hummingbird are analogous
2. similar or equivalent in some respects though otherwise dissimilar
   • brains and computers are often considered analogous
   • salmon roe is marketed as analogous to caviar