(idiomatic) In a dangerous, hazardous, or delicate situation; at risk.

(idiomatic) dangerously, hazardously, delicately

(idiomatic) Immediately and inexplicably out of sight.

(simile) Incredibly thin, at an unhealthy-looking level of thinness.

Extremely fine; so thin as to be almost invisible. / A very small difference, or advantage, when comparing two items.

scarce, or difficult to find.

plural of thin client

(computing) A minimal client that relies on the server to do most of its processing.

(letterpress typography) A metal block used to separate words, one fifth of an em in width. / (typography) In digital text, a character representing a thin space.

plural of thin space