To italicize means to format text so that it slants to the right, like this.

Writers italicize words for several reasons. You might italicize a word to show emphasis, like writing “I really want to go to the museum.” Book titles and movie titles get italicized too: The Lion, the Witch and the Wardrobe or The Wizard of Oz. Foreign words that aren't yet common in English are often italicized, like writing about eating croissants in Paris. Scientists italicize the Latin names of species, like Tyrannosaurus rex.

When you're writing by hand, you show italics by underlining instead, since you can't make your handwriting slant consistently. In typed or printed text, though, italics give your writing a professional look and help readers know which words matter most or need special attention.

The opposite of italicized text is regular upright text, which is called roman type. Most of what you read is in roman type, with italics used strategically to highlight specific words, titles, or names.