The word "narcotical" has an unusual spelling, but it follows common English phonetic rules. The IPA transcription of the word is /nɑːrˈkɒtɪkəl/. The first syllable "nar" is pronounced like the word "car," followed by the stressed syllable "co" which has a long "o" sound. The final syllable "tical" is pronounced with a schwa sound and a hard "k" sound. Overall, the spelling of "narcotical" reflects the word's origin from "narcotic" combined with the suffix "-ical," which means "relating to."
Having the power of producing drowsiness, sleep, or stupor.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.