A physical adhesive label or sticker. Also used figuratively for a negative label or stereotype attached to a person.
from Dutch Letter
瓶にレッテルを貼ってください。
Please put a label on the bottle.
彼はすぐに人にレッテルを貼る癖がある。
He has a habit of quickly labeling people.
I peel the label off the bottle before recycling it.