The answer is suffix. A reader can tell that the meaning of “obnoxious” will include “having the quality of something” because of the suffix (ous.) I hope this helped!
According to Cambridge Dictionary, a suffix can be defined as "a letter or group of letters added at the end of a word to make a new word." In this case, we have to look at the suffix -ous, which is used to modify the word into an adjective. In this case, the adjective obnoxious describes a personality.
