The Collaborative International Dictionary
Superposing
Superpose \Su`per*pose"\, v. t. [imp. & p. p. Superposed; p. pr. & vb. n. Superposing.] [F. superposer. See Super-, and Pose.]
To lay upon, as one kind of rock on another.
(Geom.) To lay (a figure) upon another in such a manner that all the parts of the one coincide with the parts of the other; as, to superpose one plane figure on another.
Wiktionary
superposing
vb. (present participle of superpose English)