Wiktionary
mid on
n. (context cricket English) a fielding position, about 70° forward of square on the leg side, between midwicket and the bowler's wicket; a fielder at this position
Usage examples of "mid on".
That was as close as he could come to asking a favor of Mid on his own.
Nobody contradicted Captain Aubrey, who in any case had gone to sleep leaning against the wheel of the cart with his hat over his face, but they wrangled so pertinaciously among themselves that Babbington invited Stephen to walk round the field to be shown the positions of square leg, long-stop, and mid on.