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molly

1 American  
[mol-ee] / ˈmɒl i /

noun

plural

mollies
  1. any of certain livebearing freshwater fishes of the genus Poecilia (formerlyMollienisia ), popular in home aquariums.


molly 2 American  
[mol-ee] / ˈmɒl i /

noun

plural

mollies
  1. a type of expansion bolt having a split, sleevelike sheath threaded at one end so that when inserted snugly into masonry the turning of the bolt draws the ends of the sheath together, thus spreading the sides.


molly 3 American  
[mol-ee] / ˈmɒl i /

noun

Slang.
  1. Often Molly MDMA.

  2. any amphetamine.


molly 4 American  
[mol-ee myool] / ˈmɒl i ˌmyul /

noun

  1. a female mule.


Molly 5 American  
[mol-ee] / ˈmɒl i /

noun

  1. a female given name, form of Mary or Milicent.


molly 1 British  
/ ˈmɒlɪ /

noun

  1. any brightly coloured tropical or subtropical American freshwater cyprinodont fish of the genus Mollienisia

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

molly 2 British  
/ ˈmɒlɪ /

noun

  1. informal an effeminate, weak, or cowardly boy or man

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of molly1

First recorded in 1930–35; shortened from New Latin Mollienisia, named after French statesman Count F. N. Mollien (1758–1850); -ia

Origin of molly2

First recorded in 1930–35; formerly a trademark

Origin of molly3

First recorded in 1975–80; origin uncertain; perhaps a shortening of black molly, a tropical aquarium fish supposedly resembling the black pills; other authorities suggest it is a shortening and alteration of molecule ( def. )

Origin of molly4

First recorded in 1980–85; generic use of the proper name

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Organisms like the salmon and molly that can tolerate a relatively wide range of salinity are referred to as euryhaline organisms.

From Textbooks • Jun. 9, 2022

In the sulfur-infused ponds of Tabasco state in Mexico lives a tiny silver slip of a fish, the sulphur molly.

From Seattle Times • Dec. 22, 2021

Whereas kingfishers would plunge into the water to pursue a molly, kiskadees would only skim the water’s surface with their beak, sparking fewer waves in response.

From Scientific American • Dec. 22, 2021

The Amazon molly evolved about 280,000 years ago from the interbreeding of two other species of fish, the Atlantic molly and the sailfin molly.

From New York Times • Feb. 26, 2021

Genie wanted to point it out to Grandpop, but Grandma had said not to mention it, and when Crab did mention it, he almost got molly whopped.

From "As Brave As You" by Jason Reynolds