Monogatari (meaning story) is a common naming element of the franchise for novels and their anime cour adaptations. This element shows up in other unrelated series titles such as Gokinjo Monogatari, Ore Monogatari, or Katanagatari.
While not always, many titles work as portmanteaus. The Bakemonogatari title for instance is made up of bakemono (化物) meaning monster or ghost and monogatari (物語) meaning legend or story. Ghostory acts as an effective English equivalent.