To keep one's own business private; to be careful, circumspect, or discreet in what one says concerning one's own deeds, situation, or thoughts.

(idiomatic) To act in one's own interests; to act in a manner advantageous primarily to oneself.

(biology, social sciences, art, philosophy) The physical, cultural, moral, or intellectual development of each individual passes through stages similar to the developmental stages of that individual's species, society, or civilization. Not taken literally since the late 19th century.

(idiomatic) To behave or act naturally, without regard to how this behavior is perceived by others. / (idiomatic) To function physically and mentally as one normally does.

(idiomatic) A stinging rebuke or rebuff.

plural of one-of-a-kind

plural of one of a kind

To take a decision that will have personally adverse consequences.

(idiomatic) A list of abbreviations, separated by commas, representing the academic qualifications and civil or military honours achieved by a person

(chiefly US, colloquial, idiomatic, somewhat vulgar) To be brave; to show some courage, especially in a situation where one has so far failed to do so.