(evolutionary theory) Natural selection.

(pharmacology, of medicine and other treatments) Legal for sale or distribution without the requirement of a prescription.

(idiomatic) To set a boundary, rule, or limit, especially on what one will tolerate.

(intransitive) To charge an exorbitant price for a service or product so that no one will purchase it. / (transitive) To force competition out of business by offering lower or discount prices.

Whoever arrives first has the best chance of success; some opportunities are only available to the first competitors.

(idiomatic) A situation in which somebody comments on or accuses someone else of a fault which the accuser shares.

(idiomatic) To depart hastily or unannounced; to escape or flee. / (of a bird) To escape from a pen or similar enclosure.

(baseball) A home run that does not leave the stadium.

A system of pleating a kilt in which a particular vertical stripe of the tartan pattern is selected and the pleats are arranged so that this chosen stripe runs down the center of each pleat.

(idiomatic) To patrol on the job, especially as a police officer or guard.