Other forms: spheres
A sphere is a perfectly round solid — a ball, an orange, a marble, a bubble of soap. Every point on the surface sits the same distance from the centre, which is what separates it from an egg or a disc.
Maths keeps the word exact: the volume of a sphere, a sphere of radius three. Everyday English uses it for the ground a person or an institution covers — her sphere of work, outside my sphere, the private sphere and the public sphere. Sphere of influence is the fixed political phrase, for the region a large country expects to control. Do not swap it with circle: a circle is flat, a sphere is solid, and a hemisphere is half a sphere, which is how the northern hemisphere got its name. The adjective is spherical.
1nounsphereA perfectly round solid shape.
“The lamp was a frosted glass sphere hanging on a wire.”
2nounareaAn area of activity, knowledge or influence.
“Hiring is outside my sphere, and I told him so.”
sphere is a solid shape.
Greek σφαῖρα meant a ball or a globe, and where Greek got it nobody knows. Latin carried it on as sphaera — a ball, a globe, and also the celestial sphere, the heavens pictured as one great round shell. Old French sphere, Middle English spere, and here it still is, meaning ball.
Middle English
spere
English, today
sphere
From Middle English spere. From Middle English spere, from Old French sphere, from Latin sphēra, earlier Latin sphaera (“ball, globe, celestial sphere”), from Ancient Greek σφαῖρα (“ball, globe”), of unknown origin. Not related to superficially similar Persian سپهر (“sky”). cliewen, þoþor, and æppel.
Etymology from Wiktionary, CC BY-SA