semicircle

UK: /ˈsɛmisɜː^rk^əl/ US: /ˈsɛmɪˌsɝkəl/ ,(sem′i sûr′kəl)

WordReference Random House Learner's Dictionary of American English © 2025

sem•i•cir•cle /ˈsɛmɪˌsɜrkəl/   n. [countable]

1. half of a circle.
2. anything having or arranged in the form of a half of a circle:
   The class made a semicircle around the teacher.

sem•i•cir•cu•lar /ˌsɛmiˈsɜrkyəlɚ/  adj. 

WordReference Random House Unabridged Dictionary of American English © 2025

sem•i•cir•cle  (sem′i sûr′kəl), n. 

Also called sem•i•cir•cum•fer•ence  (sem′ē sər kum′fər əns, -frəns, sem′ī-). half of a circle; the arc from one end of a diameter to the other.
1. anything having or arranged in the form of a half of a circle.

• Latin sēmicirculus. See semi-, circle
• 1520–30

sem•i•cir•cu•lar  (sem′i sûr′kyə lər), adj.  sem′i•cir′cu•lar•ly, adv. 
sem′i•cir′cu•lar•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

semicircle / ˈsɛmɪˌsɜːk^əl/ noun

1. one half of a circle
2. half the circumference of a circle
3. anything having the shape or form of half a circle

semicircular / ˌsɛmɪˈsɜːkjʊlə/ adjective