early 13c., "official residence of an emperor, king, archbishop, etc.," from Old French palais "palace, court," from Medieval Latin palacium "a palace" (source of Spanish palacio, Italian palazzo), from Latin palatium "the Palatine hill," in plural, "a palace," from Mons Palatinus "the Palatine Hill," one of the seven hills of ancient Rome, where Augustus Caesar's house stood (the original "palace"), later the site of the splendid residence built by Nero. In English, the general sense of "splendid dwelling place" is from late 14c.
The hill name probably is ultimately from palus "stake," on the notion of "enclosure." Another guess is that it is from Etruscan and connected with Pales, supposed name of an Italic goddess of shepherds and cattle.
A grand venue for something •Always ironically used of a fairly seedy though perhaps ornate place (1834+)
Used now only of royal dwellings, although originally meaning simply (as the Latin word palatium, from which it is derived, shows) a building surrounded by a fence or a paling. In the Authorized Version there are many different words so rendered, presenting different ideas, such as that of citadel or lofty fortress or royal residence (Neh. 1:1; Dan. 8:2). It is the name given to the temple fortress (Neh. 2:8) and to the temple itself (1 Chr. 29:1). It denotes also a spacious building or a great house (Dan. 1:4; 4:4, 29: Esther 1:5; 7:7), and a fortified place or an enclosure (Ezek. 25:4). Solomon's palace is described in 1 Kings 7:1-12 as a series of buildings rather than a single great structure. Thirteen years were spent in their erection. This palace stood on the eastern hill, adjoining the temple on the south. In the New Testament it designates the official residence of Pilate or that of the high priest (Matt. 26:3, 58, 69; Mark 14:54, 66; John 18:15). In Phil. 1:13 this word is the rendering of the Greek praitorion, meaning the praetorian cohorts at Rome (the life-guard of the Caesars). Paul was continually chained to a soldier of that corps (Acts 28:16), and hence his name and sufferings became known in all the praetorium. The "soldiers that kept" him would, on relieving one another on guard, naturally spread the tidings regarding him among their comrades. Some, however, regard the praetroium (q.v.) as the barrack within the palace (the palatium) of the Caesars in Rome where a detachment of these praetorian guards was stationed, or as the camp of the guards placed outside the eastern walls of Rome. "In the chambers which were occupied as guard-rooms," says Dr. Manning, "by the praetorian troops on duty in the palace, a number of rude caricatures are found roughly scratched upon the walls, just such as may be seen upon barrack walls in every part of the world. Amongst these is one of a human figure nailed upon a cross. To add to the 'offence of the cross,' the crucified one is represented with the head of an animal, probably that of an ass. Before it stands the figure of a Roman legionary with one hand upraised in the attitude of worship. Underneath is the rude, misspelt, ungrammatical inscription, Alexamenos worships his god. It can scarcely be doubted that we have here a contemporary caricature, executed by one of the praetorian guard, ridiculing the faith of a Christian comrade."