The correct spelling of the word is actually "cynical." It is pronounced /ˈsɪnɪk(ə)l/ with the stress on the first syllable. The word describes a skeptical or negative attitude towards something, often with a belief that people are motivated by self-interest. It is commonly used in political or social commentary to critique institutions or individuals who are perceived as hypocritical or self-serving. Remember, while "sinical" may seem like a plausible variant, stick to the correct spelling "cynical" to ensure accurate communication.
• Pert. to a sine; versed sine, the segment of the diameter intercepted between the sine and the extremity of the arc.
• See sine 1.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.