One way to hold this word: a line that fails to connect. Put a fact next to the question in hand and look for the thread between them; if there is no thread, the fact cannot pull anything, so it carries no weight here. That is irrelevance — not being wrong, just not being joined on.
One branch
接不上的狀態，和接不上的那個東西
兩個意思共用同一個畫面，差別只在你指的是那條斷掉的連結，還是線那頭的東西。
noun · C1
The fact that something has no connection with the subject you are talking about or the situation you are dealing with, and so does not matter there. Used without a or an, and often as 'the irrelevance of something'.
無關；不重要