IPA: //ˌdɛkəˈmɛθəniəm//
KK: /dɛkəˈmɛθəniəm/
A specific drug that is used to cause loss of sensation or consciousness during medical procedures.
The doctor administered decamethonium to the patient before the surgery.
Decamethonium is formed from "deca-" (from Greek "deka", meaning ten) and "methonium" (derived from "methyl" which comes from Greek "methylos", meaning wine alcohol, and the suffix "-onium" indicating a positively charged ion). The word refers to a compound that contains ten carbon atoms in its structure, specifically in the context of a quaternary ammonium compound.
Think of 'deca-' meaning ten, and 'methonium' relating to a type of ion — this helps you remember that decamethonium is a compound with ten carbon atoms.
No commonly confused words.