1. To lay, place, or position an image of someone or something onto another image of someone or something. We superimposed a picture of the Eiffel Tower on the moon. The actress is suing the tabloid for superimposing her face onto the body of an adult film star performing a sexual act.

2. To add or insert someone, oneself, or some element onto something else in an intangible or psychological manner. I was bedridden for most of my childhood, so I spent a lot of time superimposing myself onto the main characters of adventure and romance stories. You've got to be careful not to superimpose your own ideals and expectations on your kids' lives too much—you've got to let them figure things out for themselves.