conchoscopen.
Etymology: < concha n. 4c + -scope comb. form.Previous versions of the OED give the stress as: ˈconchoscope.
1876 tr. B. Fraenkel in tr. H. W. von Ziemssen et al. IV. 58 Wertheim's ‘Conchoscope’, with which I can see scarcely anything.
This entry has not yet been fully updated (first published 1891; most recently modified version published online March 2021).