-scopicalcomb. form
Primary stress is attracted to the first syllable of this combining form and vowels may be reduced accordingly; see e.g.
periscopical adj.Origin: Formed within English, by derivation. Etymons: -scope comb. form, -ical suffix.
Etymology: < -scope comb. form + -ical suffix. Compare -scopic comb. form.Formations are found from the late 17th cent., e.g. microscopical adj., telescopical adj. Formations frequently have parallels in -scopic comb. form (which are in some cases first attested later); compare discussion at -ical suffix.
This is a new entry (OED Third Edition, November 2010; most recently modified version published online September 2018).