Different prefixes, roots, or suffixes may have the same meaning. For example, the prefixes bi-, di-, and duo- all mean “two.”

What does Myo in the word myocarditis means?

The prefix 'myo' means muscle, followed by the root 'card' which means heart and then the suffix 'itis' means inflammation. So word parts provide the meaning of myocarditis: inflammation of the heart muscle.

What is the suffix that means to measure?

The suffix -meter means "measure or measuring instrument."