What is the tonic syllable?

In linguistics and phonetics, the tonic syllable is the stressed syllable in a word or phrase. It is the syllable that receives the greatest amount of prominence or emphasis when spoken. The tonic syllable is often the one that contains the main stressed vowel sound in a word. For example, in the word "computer," the tonic syllable is the second syllable, "put," which is where the main stress falls.