(ecology) A change in population or community structures that occurs at the boundary of two or more habitats.

(physics) The predicted spontaneous creation of particle-antiparticle pairs in the presence of an extremely strong electric field.

(philosophy) The situation where an otherwise legitimate act (for example, relieving a terminally ill patient's pain) may also cause an effect one would otherwise be obliged to avoid (e.g. sedation and a slightly shortened life).

plural of effective altruist

(ethics, philosophy) A proponent of effective altruism ("a philosophy and social movement that advocates the use of evidence and reasoning to determine the most effective ways to benefit others").

The psychophysical phenomenon that an intentional or willed movement is slower than an automatic or reactive one.

(psychology) The phenomenon that students who teach others learn at a better quality than students who don't teach.

(medicine, pathology) A cluster of personality changes caused by the extrapyramidal effects of the medication haloperidol, mimicking parkinsonism, hypomimia, bradykinesia, and flat affect.

(theater, literature) According to Bertold Brecht, performance in such a way that the audience is hindered from simply identifying itself with the characters in the play, and must evaluate their actions on an overt, conscious level.

Nitrogen narcosis.