The word "fancy" has several meanings, depending on its context.
1) It can be used as a verb to describe an action or movement - for example, "She fancied a walk in the park." In this case, it means she wanted or desired a walk in the park.
2) As an adjective, "fancy" can mean elaborate, decorative, or showy - for instance, "The restaurant has a fancy menu with expensive dishes." Here, it implies that the menu is ornate and sophisticated.
3) In its noun form, "fancy" can refer to an idea or notion - as in, "He had a fancy to travel around the world." This means he had a desire or inclination to go on such a journey.