exsecutorium Save DMLBS exsecutorium (exe-) , ordinal, service-book. Cf. exsecutio 2, exsecutor 2. 1446 tria vetera missalia, ‥ unum vetus portiphorium, unum processionale, unum executor[ium] officii, unum collectuarium Cl 296 m. 26d..