Bones from arm and tibia oddly missing (5)
I believe the answer is:
radii
'bones' is the definition.
(radius is a kind of bone)
'arm and tibia oddly missing' is the wordplay.
'oddly missing' means one should take alternating letters (letters in odd-numbered positions removed).
'arm'+'and'+'tibia'='armandtibia'
The alternating letters of 'armandtibia' are 'RADII'.
'from' acts as a link.
(Other definitions for radii that I've seen before include "parts for arms" , "Straight lines from the centre to the surface of a sphere" , "Geometrical lines" , "Spokes of a circle" , "Spokes of wheel - bones of arm" .)