1. To play with, to joke or to jest at, dally with, to touch lightly upon a subject.
2. To refer (a thing) fancifully or figuratively, to compare symbolically, to (something else): "Kirk told Cathy that he was interested in hearing more about the technology that she alluded to in her presentation."
3. To have an oblique, covert, or indirect reference, to point as it were in passing.
4. To make an indirect or passing reference, to glance at, refer indirectly to: "He was alluding to his first wife."
5. The OED says that allude is often used ignorantly as if it were equal to "refer" in its general sense.
6. Etymology: from Middle French alluder; from Latin alludere, "to joke, to jest"; from ad-, "to" and ludere, "to play". Originally "to mock", later, "to make a fanciful reference to"