Definitions for ortho-

This page provides all possible meanings and translations of the word ortho-

Random House Webster's College Dictionary

or•thoˈɔr θoʊ(adj.)

  1. pertaining to or occupying two adjacent positions in the benzene ring.

    Category: Chemistry

    Ref: Compare meta , 1 2 para2. 1 3

Origin of ortho:

1875–80; independent use of ortho -


  1. a combining form meaning “straight,”“upright,”“right,”“correct”:

    orthodontics; orthopedic.

    Category: Affix

  2. a combining form used in the name of the most hydrated acid in a given series: orthoboric acid. a combining form used in the names of benzene derivatives in which the substituting group occupies the ortho position in the benzene ring.

    Category: Affix, Chemistry

    Ref: Compare meta- (def. 2a), 3 2 1 pyro- (def. 2a). 2 2 1; Also, esp. before a vowel, orth- 1 .

Origin of ortho-:

< Gk, comb. form of orthós straight, upright, correct


  1. ortho-(Prefix)

    straight, right, proper

  2. ortho-(Prefix)

    Having an extra proportion of water

  3. Origin: ὀρθός.


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