(usually of relative importance, of degree, quantity or measure) In a double manner; with twice the severity or degree. / In two ways / (obsolete) with duplicity

(arithmetic) Leaving no remainder when divided by 4; divisible by 4.

Both urinarily and faecally incontinent; having double incontinence.

(mathematics) biinfinite

(linguistics) Synonym of ditransitive

(programming, of a data structure) Whose elements each link to the previous and the next element.

(physics, of a transuranic nuclide) Having filled shells of both protons and neutrons and therefore having extra stability and a longer half-life than normal.

(chemistry, American spelling) Water where both the hydrogen and oxygen atoms have been replaced by less common isotopes.