(physics) The ratio of the average mass per atom of the naturally occurring form of an element to 1/12 of the mass of a carbon-12 atom. Symbol Aᵣ; abbreviation RAM or r.a.m. For elements with several isotopes, the most stable isotope is treated as the representative.

(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.

A blood relative who shares roughly an eighth of a person's DNA, such as a great-grandparent, first cousin, half-aunt, half-uncle, half-niece, half-nephew, or great-grandchild.

A blood relative who shares roughly a quarter of a person's DNA, such as a grandparent, aunt, uncle, half-sibling, grandchild, niece, or nephew.

A blood relative who shares roughly half a person's DNA, such as a parent, full sibling, or child.

plural of first-degree relative

plural of third-degree relative

plural of second-degree relative

plural of relative pseudo-complement