diametrical

American  

[dahy-uh-me-tri-kuhl] / ˌdaɪ əˈmɛ trɪ kəl /

Also diametric

adjective

1. of, relating to, or along a diameter.

2. in direct opposition; being at opposite extremes; complete.

   diametrical opposites; a diametrical difference.

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Other Word Forms

Derived Forms

• undiametric
  adjective
• undiametrical
  adjective
• undiametrically
  adverb
• diametrically
  adverb

Etymology

Origin of diametrical

1545–55; < Greek diametrik ( ós ) ( diámetr ( os ) diameter + -ikos -ic ) + -al ¹

Explanation

In geometry, the adjective diametrical has to do with a straight line running through the middle of a circle — all diametrical lines will intersect at the very center. Aside from its mathematical meaning, you an also use this word to emphasize how opposed two things (or people) are. If you and your sister couldn't possibly be more different (she's a morning person, while you're a night owl; she's outgoing, you're an introvert), you can say you're diametrical opposites. The root of diametrical is the Greek diametros, "diagonal of a circle."