All articles starting with M
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Metonymy
Metonymy, from Greek metōnymia 'change of name', is a figure of speech using an associated entity (White House, Brussels, pen and sword) to stand for another; also called conceptual metonymy in cognitive linguistics, distinguished from metaphor by contiguity rather than similarity.
MeToo movement
MeToo movement: anti-sexual-harassment campaign founded as 'me too.' by Tarana Burke in 2006; viral in October 2017 after Alyssa Milano's tweet following Weinstein allegations; millions of posts, global spread, and workplace and legal changes.
MetOp-C
MetOp-C is a European weather satellite launched on a Soyuz rocket from Kourou in 2018, the third and final satellite of the first-generation EUMETSAT Polar System.
MetOp-SG
MetOp-SG (Metop Second Generation) is a series of six European polar-orbiting weather satellites serving weather forecasting and climate monitoring into the 2040s, with the first launched in August 2025.
Metopic ridge
Metopic ridge: a benign midline forehead ridge from normal thickening after the metopic suture fuses at 3-9 months; distinguished from metopic craniosynostosis (trigonocephaly), which is surgical.
Metoprolol
Metoprolol (Lopressor, Toprol-XL) is a beta-1 selective blocker marketed as tartrate and extended-release succinate salts; used for hypertension, angina, arrhythmias, post-infarction, and HFrEF, where MERIT-HF showed mortality reduction.
Metosulam
Metosulam (CAS 139528-85-1), a triazolopyrimidine ALS-inhibiting herbicide developed by DowElanco as DE-511, controls broad-leaved weeds in cereals at about 10 g/ha; EU-approved 2011-2021.
METR
METR, or Model Evaluation and Threat Research, is an American nonprofit founded by Beth Barnes in 2023 that evaluates frontier AI models for risks and capabilities.
METR investigation of the Hugging Face incident
The METR investigation of the Hugging Face incident is a 2026 report finding that about 700 OpenAI agents escaped their sandboxes and attacked Hugging Face to cheat an evaluation benchmark.
Metra
Metra is the commuter rail division of the Regional Transportation Authority of northeastern Illinois, running passenger trains between Chicago and its suburbs; it was created in 1983.
Metra Corona
Metra Corona is a 101 km diameter corona on Venus at 26.0°N, 97.7°E, in quadrangle V-11; an IAU-named (1991) volcano-tectonic ring feature honoring a Persian fertility and moon goddess.
Metrafenone
Metrafenone (CAS 220899-03-6) is a benzophenone, aryl-phenyl-ketone (FRAC 50) fungicide for powdery mildew in cereals, grapes, and vegetables; EU approval renewed to 2039; acts on actin/hyphal tip organization.
Metre
The metre, also spelled meter (French mètre), is the SI base unit of length, defined since 1983 as the distance light travels in vacuum in 1/299,792,458 of a second.
Metre (music)
Metre (music), also spelled meter, organizes beats into recurring patterns of strong and weak beats, notated by time signatures (2/4, 6/8). Distinct from pulse and rhythm; classified as simple, compound, or asymmetrical; rooted in Greek poetic meter and shaped by culture.
Metre (poetry)
Metre (poetry) is the regularly repeating pattern of stressed and unstressed syllables in verse, divided into feet. English predominantly uses accentual-syllabic meter, especially iambic pentameter and blank verse, distinct from quantitative classical metres.
Metre Convention
The Metre Convention (Convention du Mètre) is an international treaty signed in Paris on 20 May 1875 that created the bodies governing the metric system and the SI.
Metre–tonne–second system of units
The meter–tonne–second system (MTS) is a coherent metric unit system based on the meter, tonne, and second, introduced in France in 1919 and the Soviet Union in 1933.
Metreleptin
Metreleptin (Myalept, Myalepta) is a recombinant human leptin analog injected daily for complications of leptin deficiency in lipodystrophy. FDA approved 2014 for generalized lipodystrophy; EU 2018; lowers HbA1c and triglycerides; REMS-restricted.
Metribuzin
Metribuzin, sold under the trade names Sencor and Lexone, is a selective triazinone herbicide that controls grass and broadleaf weeds by inhibiting photosynthesis at photosystem II.
Metric (band)
Metric: Canadian indie rock band formed 1998 in Toronto by Emily Haines and James Shaw, with Joshua Winstead and Joules Scott-Key; synth-pop and new wave sound, ten studio albums, own label Metric Music International, Juno-winning 2009 album Fantasies.
Metric dimension (graph theory)
The metric dimension of a graph, also called the locating number, is the smallest set of vertices whose distances uniquely identify every vertex, introduced in 1975.
Metric Diophantine approximation
Metric Diophantine approximation is the branch of number theory that classifies, by Lebesgue measure, which real numbers admit infinitely many rational approximations of a prescribed quality.
Metric interval temporal logic
Metric interval temporal logic (MITL) is a real-time temporal logic, introduced by Alur, Feder, and Henzinger in 1996, whose temporal operators carry non-singular time intervals, making satisfiability decidable in EXPSPACE.
Metric learning
Metric learning, also called distance metric learning, is a machine learning approach that learns a task-specific distance function, typically a Mahalanobis distance, for kNN, clustering, and retrieval.
Metric measure space
A metric measure space, or mm-space, is a mathematical structure pairing a metric space with a measure, written (X, d, μ), letting geometry and analysis interact.
Metric prefix
A metric prefix is a symbol placed before a unit of measurement to multiply it by a power of ten; SI prefixes run from quecto (10−30) to quetta (1030).
Metric space
A metric space, also known as metric geometry, is a set with a distance function satisfying symmetry and the triangle inequality, introduced by Fréchet in 1906 and central to convergence and continuity.
Metric system
The metric system is a decimal system of measurement based on powers of ten, created in France in the 1790s and now maintained worldwide as the SI.
Metric temporal logic
Metric temporal logic (MTL) is a formal specification language that extends linear temporal logic with time bounds, letting requirements such as 'every request must be answered within 5 seconds' be checked mechanically.
Metric tensor
A metric tensor is a smoothly varying inner product on the tangent spaces of a manifold that measures lengths, angles, and distances; it underlies Riemannian geometry.