ˈbäˌnäḵ-, -_nək- noun
Usage: usually capitalized B
Etymology: after Stefan Banach died 1945 Pol. mathematician
: a linear algebra over the field of real or complex numbers that is also a Banach space for which the norm of the product of x and y is less than or equal to the product of the norm of x and the norm of y for all x and y belonging to it