extraneous
Extraneous (adj) means not relevant or necessary to the matter at hand; irrelevant. Example: “The editor cut several extraneous details that slowed the story down.”
How to use extraneous
Learner’s notesIn plain EnglishSomething unnecessary or off-topic that doesn't belong to the main point.
Fill the gap
Can you complete this real example?
The editor cut several _____ details that slowed the story down.
Etymology
From Latin extrāneus, "external, foreign, from outside" — the same root that gives us "strange" and "estrange."