(dated) Synonym of Mothering Sunday: the fourth Sunday in Lent.

The point or area on a map described by the numbers or letters indicated.

(engineering) An alloyant used to refine grains in a cast macrostructure

plural of angle of reflection

plural of angle of refraction

plural of refractory metal

(metallurgy) A metal, such as molybdenum or tungsten, with a high refraction, and hence a high melting point.

plural of reflexive verb

Alternative spelling of backreference

(biology) The period, after excitation, during which a membrane recovers its polarization and is not able to respond to a second stimulus.