Question

word part list
algia
dynia
itis
lith
logist
neuro
osteal
ot
oto
plasty
rrhea
sclerosis
scope
device for visualizing the ear

Explanation:

The word part "oto" means ear, and "scope" means an instrument for viewing or observing. Combining these two word parts gives "otoscope", which is a device for visualizing the ear.

Answer:

otoscope