Definitions for orthoˈɔr θoʊ
Random House Webster's College Dictionary
pertaining to or occupying two adjacent positions in the benzene ring.
Ref: Compare meta , 1 2 para2. 1 3
Origin of ortho:
1875–80; independent use of ortho -
a combining form meaning “straight,”“upright,”“right,”“correct”:
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
An isomer of a benzene derivative having two substituents adjacent on the ring
A certain type of flat eyepiece
An orthochromatic plate