[under the counter] {adv. phr.}, {informal} Secretly (bought or sold). * […]

[up a tree] {adv.} or {adj. phr.} 1. Hunted or chased […]

[up against it] {adj. phr.}, {informal} Faced with a great difficulty […]

[up for grabs] {adj. phr.}, {informal} Available for anyone to try […]

[up front] (1) {n.}, {slang}, {informal} The managerial section of a […]

[up front] (2) {adj.}, {slang}, {informal} Open, sincere, hiding nothing. * […]

[up in the air] {adj.} or {adv. phr.} 1. {informal} In […]

[up one's sleeve] or [in one's sleeve] {adv. phr.} 1. Hidden […]

[up the creek] or [up the creek without a paddle] {adj. […]

[up tight] or [uptight] {adj.}, {slang}, {informal} Worried, irritated, excessively eager […]