(immunology) An aspect of the innate immune system that supplements the actions of the antibodies and phagocytic cells in clearing out pathogens from an organism

(mathematics) The relative pseudo-complement of a given element (of a Heyting algebra) with respect to the least element — the "zero" of that algebra.

(linear algebra, functional analysis) The set of all vectors which are orthogonal to a given set of vectors.

(biology) The air that can be drawn into the lungs in addition to the tidal air, by the deepest possible inhalation.

plural of complement system

(immunology) Any of a group of plasma proteins that bring about the destruction of pathogens through opsonization or assault on the cell membrane.

plural of complement protein

The number which, added to the given n-digit number in radix r, results in rⁿ-1. In binary (r=2), this is the ones' complement; in decimal (r=10), this is the nines' complement.

(mathematics) The residual operation of a Heyting algebra when considered as a residuated lattice whose monoid operation is the meet operation. Equivalently, the relative pseudo-complement of a with respect to b is the supremum of the set of all z such that z∧a⩽b, where ∧ denotes the meet operation of the given Heyting algebra.

plural of absolute complement