(medicine) X-ray presentation of air compressing the frontal lobes of the brain, resulting in a tented appearance, indicative of pneumocephalus.

A semaphore-like signalling device positioned at a road intersection or pedestrian crossing to indicate when to drive, ride or walk, similar in purpose to a traffic light, often run by a person rather than automatic.

A sign language commonly used in Sweden.

(US, slang) The sign of a Dairy Queen fast food restaurant.

A certain Catalan-based sign language, used predominantly in Catalonia and Barcelona.

(mathematics) the symbol ±, meaning "plus or minus", used to indicate the precision of an approximation (as in "The result is 10 ± 0.3", meaning the result is anywhere in the inclusive range from 9.7 to 10.3), or as a convenient shorthand for a quantity with two possible values of opposing sign and identical magnitude (as in "The roots of the equation x² - 4 = 0 are ±2").

A language that uses hands, facial expressions, and other bodily behavior to communicate both concrete and abstract ideas; some signs are based on English words, but ASL syntax and grammar are not based on English. ISO 639-3 code: ase.

(mathematics) the symbol ∓, meaning "minus or plus", used alongside the plus-minus sign to show that a negative value is to be taken where the positive value is indicated by the plus-minus sign, and vice versa (as in (x ± 1) / (x ∓ 2), which means (x + 1) / (x - 2) and (x - 1) / (x + 2)).

(intransitive, idiomatic) To formalize an agreement.

(military) A call sign that identifies a tactical command or tactical communication facility.