plural of modus operandi

present participle of co-operate

(astronomy, optics) An optical system in telescopes that reduces atmospheric distortion by dynamically measuring and correcting wavefront aberrations in real time, often by using a deformable mirror.

resembling opal in its iridescence; having a milky white iridescence.

a clear to white liquid secreted by sea hares (genus Aplysia) that becomes viscous upon contact with water / (mineralogy) any of several minerals resembling opal, including a variety of yellow chalcedony

A problem that has been posed in a field of study such as mathematics or theoretical computer science, but whose answer is not yet known.

(initially derogatory) A subgenre of speculative fiction or science fiction that emphasizes space travel, romantic adventure, and larger-than-life characters often set against vast exotic settings.

(idiomatic) A theatrical production, film, or program on radio or television depicting adventures of characters in the American Old West; a western.

Something that is in its beta stage, or being tested.

Pertaining to a product sold by merchants at a discount, because the item was returned but found not to be defective.