Originally a pet form of Robert, from the short form Rob + the diminutive suffix -in (of Old French origin), but now nearly always used as an independent name. In recent years it has been increasingly used as a girl's name, partly under the influence of the vocabulary word denoting the bird.
Italian: 1. from an old Tuscan personal name, Saccus, a reduced form of the Old Testament name Isaccus (see Isaac). 2. metonymic occupational name for a maker of sacks or bags, from sacco ‘sack’, or nickname for someone thought to resemble a sack. 3. habitational name from Sacco in Salerno province.