The Collaborative International Dictionary of English v.0.48:
Similar \Sim"i*lar\, a. [F. similaire, fr. L. similis like,
similar. See Same, a., and cf. Simulate.]
1. Exactly corresponding; resembling in all respects;
2. Nearly corresponding; resembling in many respects;
somewhat like; having a general likeness.
3. Homogenous; uniform. [R.] --Boyle.
Similar figures (Geom.), figures which differ from each
other only in magnitude, being made up of the same number
of like parts similarly situated.
Similar rectilineal figures, such as have their several
angles respectively equal, each to each, and their sides
about the equal angles proportional.
Similar solids, such as are contained by the same number of
similar planes, similarly situated, and having like
inclination to one another.