O
air line
ambit
amplitude
annular muscle
annulus
approach
area
areola
asymptote
aureole
axis
beeline
bigness
body
bore
bottleneck
breadth
bulk
caliber
carry
chaplet
chord
circle
circuit
circumference
circus
closed circle
collision course
compass
concentralization
concentration
concourse
concurrence
confluence
conflux
congress
convergence
converging
corona
coronet
coverage
crossing
crown
cycle
depth
diadem
diagonal
diameter
artiodactyla
radii
ray
arm bone
part
region
straight line
support
radial
radiate
radiation
altitude
angle
arc
density
dimension
distance
elevation
height
hike
interval
length
perimeter
range
rotation
segment
stretch
thickness
velocity
width
zone