The spelling of the word "appendicle" is often confused with "appendix." However, the two words have different meanings. While the appendix refers to a small, worm-shaped organ in the human body, the appendicle refers to a small appendage or addition. The correct pronunciation of "appendicle" is /əˈpɛndɪk(ə)l/, with the emphasis on the second syllable. The phonetic transcription of this word shows that it is pronounced with a schwa sound in the first syllable and a "k" sound in the second syllable.
A small appendage.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.