There appears to be a further definition of "retract" which is used in the context of topology. See the parenthetical note on Definition:Cobordism/Homotopy.
That would require this page to be a disambiguation, but I am out of my depth in both category theory and manifold theory, so I'm not going near it -- just flagging up that it needs to be addressed. --prime mover (talk) 12:39, 1 May 2014 (UTC)
- I suggest that we worry only once the background to actually start covering algebraic topology (where this notion indeed exists) is in place. My work on Munkres will serve as a foundation. In ten years, the follow-up will likely be Hatcher's standard text or something similarly thorough. — Lord_Farin (talk) 17:36, 1 May 2014 (UTC)