allo-

¹ American  

especially before a vowel, all-

1. a combining form meaning “other,” used in the formation of compound words (allotrope ) and in chemistry to denote the more stable of two geometric isomers.

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allo. ² American  

abbreviation

1. allegro.

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allo- British  

combining form

1. indicating difference, variation, or opposition

   allopathy

   allomorph

   allophone

   allonym

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Usage

What does allo- mean? Allo- is a combining form used like a prefix meaning “other” or "different." It is frequently used in a variety of medical and scientific terms.In chemistry, allo- denotes the more stable of two geometric isomers. Isomers are molecules that contain the same numbers of the same kinds of atoms but in which the atoms have different structural arrangements.Allo- comes from Greek állos, meaning “other.” This word’s distant cousins in Latin, alius and alter, which have similar definitions, give us words such as alien and alternative. The opposite of allo- is the form auto-, from Greek autós, “self.”What are variants of allo-?When combined with words or word elements that begin with a vowel, allo- typically becomes all-, as in allonym.Want to learn more? Read our Words That Use all- article.

Etymology

Origin of allo-

< Greek, combining form of állos other; cognate with Latin alius, else