Why is a hemisphere not called a demisphere or semisphere?

Just wondering because hemi, demi, and semi all mean the same thing.

4 Answers

  • Isabel
    Lv 7
    7 years ago
    Favourite answer

    While the dictionary may define them as similar meaning, it was early use that defined the use of words. These are not used interchangeably, even though their meanings are written as the same. A semi-circle would never be called a demi circle. It's simply the use of the word that makes the difference and it's a subtle difference. Frankly in the case of dictionaries, I think they fall short of the nuances of proper definition and usage of these prefixes. And considering, the prefix qualifies the word that follows and prefixes themselves are not actual words so their interpretation would waver.

    This is just one of those rules that you have to take as it is, it's common usage over thousands of years that determined how we use them. It's kind of a similar argument to the use of un or non - they are both defined as not, but you would be more likely to use unkind rather than non-kind. And it's because of common usage.

  • 5 years ago

    Three major reasons.

    Hemi comes from Greek origin. The Greeks big on geometry and spheres are geometrical figures

    Hemi comes from Greek origins. The root word Sphere also comes from Greek origins. Matching the origins of roots and prefixes is grammatically proper.

    The prefix hemi doesnt just mean one-half. It also implies symmetry. A sphere is symmetrical no matter where you cut it, so any half of it is a hemisphere. More than that, though, hemi implies a cut through the longest axis. A human being that is a hemiplegic is someone who is paralyzed in the left or right half of the body, not the top or bottom half (paraplegic). Also, even though hemi is less frequently used in general than semi, it is more often used in a technical sense.

  • Anonymous
    7 years ago

    The answer lies in the etymology of the word "hemisphere":

    From Latin hemisphaerium, from Ancient Greek ἡμισφαίριον (hēmisphairion), from ἡμι- (hēmi-, “half”) + σφαῖρα (sphaira).


    Both "ἡμι-" (hemi-) and "-σφαίριον" (-sphairion) originated in Ancient Greek and the combination transferred smoothly into Latin as "hemisphaerium" and thence to French and English.

    The prefix "semi" is Latin, not Greek, in origin and gave birth to words in Latin such as "semi-homo" (half-man) and "semi-mortuus" (half-dead).

    The prefix "demi" is mainly associated with French, which has words such as "demi-heure" (half-hour) and "demi-solde" (half-pay).

    The rule whether to apply "hemi-", "demi-" or "semi-" to express "half-ness" in a word is first and foremost dictated by historical precedent: did the word exist in Ancient Greek or Latin, or is it of more modern provenance? If the former, there is no need to change "semicircular" to "hemicircular" or "demi-circular", because Latin's word for "circle" is "circulus". If the latter, then people can argue to their heart's content which prefix to use.

    Finally, what's the term for a sixty-fourth musical note, drawn as a crotchet with four tails? A hemidemisemiquaver, of course! The term "quaver" is neither Latin nor Greek, but Germanic in origin, so you can break the rules a little and use all three prefixes meaning "half" in this case.

  • Andrew
    Lv 6
    7 years ago

    I thought we were now supposed to use 'semisphere'.

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