The word incense has two different meanings:

1. A substance that produces a fragrant smell when burned. Incense often comes as sticks, cones, or small pieces of wood or resin. When lit, it releases aromatic smoke that fills a room with scent. Many religions use incense in their ceremonies: you might smell it burning in churches, temples, or mosques. The frankincense and myrrh that the Wise Men brought to baby Jesus in the Christmas story were valuable types of incense. Some people burn incense at home simply because they enjoy the smell.
2. To make someone extremely angry (pronounced differently, with the stress on the second syllable: in-SENSE). When something incenses you, it doesn't just annoy you; it fills you with fury. A teacher might be incensed if students cheat on a test, or parents might be incensed when they discover someone has been bullying their child. When you're incensed, you're so angry that everyone around you can tell.