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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)

alterity
nounC1+
/ɒlˈtɛrɪti/The state of being other or different; otherness.
alternant
adjectivenounC2/Technical
/ˈɔːl.tə.nənt/One of two or more things that alternate or are in a sequence of regular change.
alternate
adjectivenounverb+2B2
/ˈɔːl.tə.neɪt/ (verb), /ɔːlˈtɜː.nət/ (adjective, noun)To occur or do something by turns; to switch repeatedly between two states or actions.
alternate angles
plural-nounC2
/ˈɔːl.tə.neɪt ˈæŋ.ɡəlz/Pairs of angles formed when a straight line (transversal) crosses two other lines. They are on opposite sides of the transversal and inside (or outside) the two lines.
alternate history
nounC1
/ˈɔːltəneɪt ˈhɪst(ə)ri/A genre of fiction or a work within that genre in which historical events are imagined to have unfolded differently, often exploring 'what if' scenarios.
alternate host
nounC1-C2 / Low Frequency / Specialized
/ˈɒl.tə.neɪt həʊst/ (adj+n), /ɔːlˈtɜː.nət həʊst/ (less common)An organism (usually a plant) that serves as a necessary secondary host for the completion of a pathogen's or parasite's life cycle.
alternate plumage
nounC1-C2
/ˈɔːl.tə.neɪt ˈpluː.mɪdʒ/The second set of feathers a bird acquires in a year, distinct from the more conspicuous breeding plumage, typically worn in non-breeding seasons.
alternating current
nounC1
/ˌɔːltəneɪtɪŋ ˈkʌrənt/An electric current that reverses its direction periodically, typically many times per second, as opposed to flowing in one constant direction.
alternating group
nounC1
/ˈɔːltəneɪtɪŋ ɡruːp/A specific mathematical structure; in group theory, the subgroup of a symmetric group consisting of all even permutations.
alternating light
nounLow to Medium (Technical/context-specific)
/ˈɔːltəneɪtɪŋ laɪt/A system of lighting, especially in transportation or navigation, where lights switch on and off in a regular, repeating sequence.
alternating series
nounLow in general contexts; high in mathematical/technical contexts.
/ˈɔːltəneɪtɪŋ ˈsɪəriːz/A mathematical series in which the signs of the terms alternate between positive and negative, typically expressed as Σ (-1)^(n-1) a_n.
alternating voltage
nounC1
/ˈɔːltəneɪtɪŋ ˈvəʊltɪdʒ/An electric voltage that periodically reverses direction, typically following a sinusoidal waveform.
alternating-gradient focusing
nounVery Low
/ˈɔːltəneɪtɪŋ ˈɡreɪdiənt ˈfəʊkəsɪŋ/A technique in particle accelerator physics where magnetic fields with alternating gradients are used to focus charged particle beams.
alternation
nounC1
/ˌɔːltəˈneɪʃn/The successive occurrence of two or more things in turns; a repeated sequence or pattern of change between two or more states, options, or actions.
alternation of generations
nounC2
/ˌɔːltəˌneɪʃən əv ˌdʒɛnəˈreɪʃənz/A biological life cycle involving two or more distinct phases that alternate, typically a sexual phase and an asexual phase.
alternative
adjectivenounB1
/ɔːlˈtɜːnətɪv/A choice between two or more possibilities; one of two or more available options.
alternative conjunction
nounC1
/ɔːlˈtɜːnətɪv kənˈdʒʌŋkʃ(ə)n/A word or phrase used to connect two alternatives, typically indicating a choice between them.
alternative curriculum
nounC1
/ɒlˈtɜː.nə.tɪv kəˈrɪk.jə.ləm/An educational program designed as a substitute for a traditional or mainstream curriculum, often tailored to different learning needs, approaches, or philosophies.
alternative energy
nounB2
/ɒlˈtɜːnətɪv ˈɛnədʒi/Energy derived from natural, replenishable sources that are not fossil fuels, such as solar, wind, hydro, and geothermal power.
alternative fuel
nounC1
/ɔːlˌtɜːnətɪv ˈfjuːəl/Any non‑petroleum‑based fuel used to power vehicles or machinery, intended to reduce dependence on fossil fuels and/or environmental impact.

Showing 3601–3620 of 8734 words.