present
Heed, attend to
Assister means 'to attend' (a class, a conference, ..), or 'to help' (to be of assistance, which has the same roots).
absent
A word that has the same meaning as another word is a synonym.
Another word meaning clenched is tighten.
The meaning of a word is its "definition."
A synonym is a word with a meaning similar to that of another word.
cherish, accomplish, and attend
"It was doubtless they would have to attend the class."
Another word meaning "to influence" is "affect" or "impact."
The smallest class of sound that makes a difference in meaning is called a phoneme. Phonemes are the basic units of sound that distinguish one word from another in a particular language. Changing a phoneme can result in a change in meaning.
another word for eclectic