WordReference Random House Unabridged Dictionary of American English © 2025
ul•tra•fil•ter
(ul′trə fil′tər),USA pronunciation n.
v.t.
ul•tra•fil•tra•tion
(ul′trə fil trā′shən),USA pronunciation n.
- Chemistry[Physical Chem.]a filter for purifying sols, having a membrane with pores sufficiently small to prevent the passage of the suspended particles.
- Mathematicsa filter in a topological space, having the property that no other filter exists in the space having among its subsets all the subsets in the given filter.
v.t.
- Chemistry[Physical Chem.]to purify by means of an ultrafilter.
- ultra- + filter
'ultrafilter' also found in these entries (note: many are not synonyms or translations):