of a set $A$ in a topological space $X$
A point $x$ such that every neighbourhood of it has non-empty intersection with $A$. The set of all proximate points forms the closure $[A]$, or $\bar A$, of $A$ (cf. Closure of a set).
Proximate point. Encyclopedia of Mathematics. URL: http://www.encyclopediaofmath.org/index.php?title=Proximate_point&oldid=31526