preregular
Adjective
Meaning
preregular (not comparable)
(topology, of a space) In which any two topologically distinguishable points can be separated by neighbourhoods
Examples
Although Hausdorff spaces are not, in general, regular, a Hausdorff space that is also (say) locally compact will be regular, because any Hausdorff space is preregular.
Although Hausdorff spaces aren't generally regular, a Hausdorff space that is also (say) locally compact will be regular, because any Hausdorff space is preregular.
As it turns out, uniform spaces, and more generally Cauchy spaces, are always preregular, so the Hausdorff condition in these cases reduces to the T 0 condition.
A topological space is Hausdorff if and only if it is both preregular (i.e. topologically distinguishable points are separated by neighbourhoods) and Kolmogorov (i.e. distinct points are topologically distinguishable).
A related, but weaker, notion is that of a preregular space.
As described above, any completely regular space is regular, and any T 0 space that is not Hausdorff (and hence not preregular) cannot be regular.