circumference

Từ điển American Heritage Dictionary 4th

cir·cum·fer·ence (sər-kŭmʹfər-əns)n.
1. The boundary line of a circle.
2.
a. The boundary line of a figure, area, or object.
b. Abbr. c or circ. The length of such a boundary. [Middle English, from Old French circonference, from Latin circumferentia, from circumferēns, circumferent- present participle of circumferre, to carry around : circum-, circum- + ferre, to carry; See bher-¹ in Indo-European Roots.] cir·cum'fer·enʹtial (-fə-rĕnʹshəl) adj. 
Synonyms: circumference, circuit, compass, perimeter, periphery
These nouns refer to a line around a closed figure or area: the circumference of the earth; followed the circuit around the park; stayed within the compass of the schoolyard; the perimeter of a rectangle; a fence around the periphery of the property.

• Từ đồng nghĩa / Synonyms:
  circuit, perimeter