Agister \A*gist"er\, Agistor \A*gist"or\, n. [Anglo-Norman agistour.] (Law) (a) Formerly, an officer of the king's forest, who had the care of cattle agisted, and collected the money for the same; -- hence called {gisttaker}, which in England is corrupted into {guest-taker}. (b) Now, one who agists or takes in cattle to pasture at a certain rate; a pasturer. --Mozley & W. [1913 Webster]