15-Letter Words Containing: P,R,A,X

• a performance given extempore without planning or preparation

• antibacterial substance that is a water-soluble powder used in antiseptic soaps and toothpaste

• Any member of the Paramyxoviridae family of negative-sense single-stranded RNA viruses responsible for a number of human and animal diseases.

• The fused head and thorax of spiders and crustaceans

• extinct primitive toothed bird of the Jurassic period having a long feathered tail and hollow bones; usually considered the most primitive of all birds

• radiography using X-rays and xerographic (rather than roentgenographic) techniques

• of or relating to lexicography