Origin: 1225–75; ME < AF burgler (cf. AL burg(u)lātor), perh. < OF *borgl(er) to plunder, pillage (< Gallo-Rom *būriculāre, equiv. to *būric(āre) (Old Low Franconian *būrj(an) to dart at, pounce upon + VL *-icāre v. suffix; cf. OF burgier to strike, hit) + -ulāre v. suffix) + AF -er-er2; see -ar2
[Anglo-Norman burgler (alteration of burgesur, probably from Old French burg, borough) and Medieval Latin burgulātor (alteration of burgātor, from burgāre, to commit burglary in, from Late Latin burgus, fortified town), both of Germanic origin; see bhergh-2 in Indo-European roots.]