An engrossing story, film, book, or talk is one that holds you so tightly you forget to look up. We use this word to praise the thing itself: the plot is engrossing; the lecture was engrossing. It is the partner of engrossed — the film is engrossing; you are engrossed in it. Reviews and school writing like it, because it says more than interesting: interesting can be polite and weak; engrossing says you were taken. It is a compliment, never an insult. It has nothing to do with gross meaning “yuck,” and nothing to do with a film “grossing” money at the box office, though the spelling can trick you.