subs. phr. (colloquial).A boxed or pickled egg: as distinguished from new-laid.
1878. H. J. BYRON, Our Boys. Perkin Middlewick. [aside; taking up eggs] SHOP UNS. Sixteen a shilling. I knows em.
1893. MILLIKEN, Arry Ballads, 62, On Angling. About colds, and cock-salmons, and SHOP UNS; its one of the rummiest sights.