Not relating to the subject or situation being focused on
(of a voice or sound) high-pitched and piercing
Physically strong; muscular
Given to sudden and unaccountable changes of mood or behavior
ADJECTIVE
Extraneous - Not relating to the subject or situation being focused on
The teacher tried to focus on the day's topic, and spent a great effort making sure the class wasn't distracted by questions and comments from students about extraneous topics.