Definition of messier:
(n) :
(astronomy) As a designation, the numbered objects in Messier's catalog are prepended with his surname or the letter M.
(n) :
Charles Messier (1730-1817), a French astronomer who between 1774 and 1781 published his Catalogue of Nebulae and Star Clusters, a catalogue of deep-sky objects.
(n) :
A surname from French [in turn originating as an occupation], famously held by: