Irrelevant
Definition 1 of 3
Pro Tip 1/2
Contextual Irrelevance
Consider the subject of discussion; 'irrelevant' describes something unrelated to it. Talking about football is irrelevant during a cooking class.
Pro Tip 2/2
Conversation Misstep
Using 'irrelevant' suggests a person's input does not contribute to the topic at hand. Jane's focus on past budgets seemed irrelevant during the new project meeting.