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English Words Starting With A

8,734 entries — pick a word to see its definition, pronunciation, and usage.

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Noun Verb Adjective Adverb Plural noun Combining form Verb (transitive)Verb (intransitive)Verb (ambitransitive)

astrochemistry
nounC2
/ˌæs.trəʊˈkem.ɪ.stri/The study of the abundance and reactions of molecules in the universe, and their interaction with radiation.
astrocompass
nounVery Low
/ˈæstrəʊˌkʌmpəs/A navigational instrument that determines direction by observing celestial bodies (stars, sun, moon).
astrocyte
nounLow/Very Low
/ˈæstrə(ʊ)ˌsaɪt/A star-shaped glial cell of the central nervous system.
astrodome
nounC1
/ˈæstrəʊˌdəʊm/A large, domed stadium or structure, originally designed to be enclosed for all-weather use.
astrodynamics
nounC2
/ˌastrəʊdʌɪˈnamɪks/The branch of mechanics that deals with the motion of objects in space under the influence of gravitational and other forces.
astrogate
verb-ambitransitiveVery rare / technical
/ˈæstrəʊɡeɪt/to navigate or guide a spacecraft through space.
astrogeology
nounVery low
/ˌæstrəʊdʒiˈɒlədʒi/The scientific study of the geology of celestial bodies such as planets, moons, asteroids, comets, and other rocky objects in space.
astrograph
nounC2 (Very Rare / Technical)
/ˈæstrə(ʊ)ɡrɑːf/An instrument used for photographing the stars and other celestial bodies.
astroid
nounC2 (Very low frequency)
/ˈastrɔɪd/A specific type of curve in mathematics, shaped like a four-pointed star, generated by a point on a circle rolling inside a fixed circle with a radius four times larger.
astrolabe
nounC2
/ˈæstrəleɪb/A historical astronomical instrument used to observe the positions of celestial bodies and solve problems related to time and location.
astrology
nounC1
/əˈstrɒlədʒi/The study of how the positions and movements of celestial bodies are believed to influence human affairs and natural phenomena on Earth.
astromancy
nounRare
/ˈæstrə(ʊ)ˌmænsi/Divination or predicting the future by interpreting the positions and movements of celestial bodies (stars, planets).
astrometeorology
nounVery Low (C2+ / Academic/Specialist)
/ˌæs.trəʊˌmiː.ti.əˈrɒl.ə.dʒi/The study of how astronomical phenomena, such as planetary positions and solar cycles, influence Earth's weather and climate patterns.
astrometric binary
nounVery Low
/ˌæstrəʊˈmetrɪk ˈbaɪnəri/A binary star system where only one star is visible, but the presence of the second is inferred from the periodic wobble in the visible star's proper motion.
astrometry
nounVery low
/əˈstrɒmətri/the branch of astronomy that involves precise measurements of the positions and motions of stars and other celestial bodies
astronaut
nounB1
/ˈæstrənɔːt/A person who is trained to travel and work in a spacecraft.
astronautics
nounC1
/ˌæs.trəˈnɔː.tɪks/The science and technology of spaceflight and space exploration.
astronavigation
nounRare
/ˌæstrəʊˌnævɪˈɡeɪʃən/The science and practice of determining a vehicle's position and course by observing celestial bodies.
astronomer
nounB2
/əˈstrɒn.ə.mər/A person who studies astronomy; a scientist who observes and analyzes celestial bodies and phenomena.
astronomer royal
nounC2
/əˌstrɒn.ə.mə ˈrɔɪ.əl/A prestigious honorary title for a leading astronomer in the United Kingdom, appointed by the monarch.

Showing 7581–7600 of 8734 words.