[on an average] or [on the average] {adv. phr.} In most […]

[on an even keel] {adv. phr.}, {informal} In a well-ordered way […]

[on approval] {adv. phr.} With the understanding that the thing may […]

[on board] (2) {adv.} or {adj. phr.} On a ship. * […]

[on deck] {adv.} or {adj. phr.} 1. On a floor of […]

[on deposit] {adv. phr.} In a bank. * /I have almost […]

[on die money] {adv. phr.} Exactly right; exactly accurate. * /Algernon […]

[on faith] {adv. phr.} Without question or proof. * /He said […]

[on file] {adv. phr.} Placed in a written or electronic file; […]

[on foot] {adv.} or {adj. phr.} 1. By walking. * /Sally's […]