English Words Starting With I

• infancy

  nounB1
  /ˈɪnfənsi/The earliest stage of life, from birth to about two years old.
• infant

  adjectivenounB2
  /ˈɪnfənt/A very young child or baby, typically from birth to about one year old.
• infant apnea

  nounLow
  /ˈɪnfənt æpˈniːə/A condition where a baby, typically under one year old, experiences pauses in breathing for 20 seconds or longer, often during sleep.
• infant prodigy

  nounC1
  /ˈɪnfənt ˈprɒdɪdʒi/A very young child (infant) who displays extraordinary, adult-level abilities or talents in a specific field such as music, mathematics, or chess.
• infant school

  nounLow (C1/C2 vocabulary outside the UK or educational contexts). Common within UK-specific discourse.
  /ˈɪnfənt skuːl/A school for children aged 4 to 7, typically in the UK education system.
• infanta

  nounC2
  /ɪnˈfæn.tə/A title for a daughter of a king of Spain or Portugal, especially the eldest daughter who is not heir to the throne.
• infante

  nounVery Low (Specialist/Historical)
  /ɪnˈfanteɪ/A son of a Spanish or Portuguese monarch, other than the heir to the throne; historically, a young prince of royal blood.
• infanticide

  nounLow Frequency / Academic/Legal
  /ɪnˈfæn.tɪ.saɪd/The act of killing a very young child, specifically one under one year old.
• infantile autism

  nounVery Low / Obsolete
  /ˈɪnfəntaɪl ˈɔːtɪz(ə)m/An outdated clinical term for what is now primarily called autism or autism spectrum disorder, referring to the manifestation of autistic traits from early childhood.
• infantile paralysis

  nounLow
  /ˈɪnfəntaɪl pəˈɹæləsɪs/An outdated medical term for the acute viral disease poliomyelitis, primarily affecting children and causing muscle weakness and paralysis.
• infantilism

  nounLow (C2)
  /ˈɪnfəntɪlɪz(ə)m/A condition characterized by the persistence of childlike physical, psychological, or behavioral traits in an adult.
• infantilize

  verb-transitiveC1/C2 (Low frequency, used in specific critical or analytical contexts)
  /ɪnˈfæntɪlaɪz/To treat someone as if they were a child, denying them full adult status or responsibility.
• infantry

  nounB2
  /ˈɪnfəntri/Soldiers who fight on foot.
• infantry fighting vehicle

  nounLow (Technical / Military)
  /ˈɪnf(ə)ntri ˌfaɪtɪŋ ˈviːɪk(ə)l/A heavily armed armored combat vehicle designed to transport infantry to the battlefield and provide direct fire support during combat.
• infantryman

  nounC1
  /ˈɪnfəntrimən/A soldier who fights on foot as part of an infantry unit.
• infants' school

  nounLow Frequency / Region-Specific
  /ˈɪnfənts skuːl/A school for very young children, typically aged 5 to 7, serving as the first stage of formal education in the UK system.
• infarct

  nounC2
  /ˈɪnfɑːkt/An area of tissue that has died due to a lack of blood supply.
• infarction

  nounC1/C2
  /ɪnˈfɑːk.ʃən/The obstruction of blood flow to an organ or tissue, typically caused by a blood clot, resulting in local tissue death.
• infare

  nounRare / Obsolete
  /ˈɪnfeə/A celebration or entertainment held to welcome a newly married couple to their new home; a housewarming.
• infatuate

  adjectivenounverbverb-transitiveC1
  /ɪnˈfætʃ.u.eɪt/To inspire with a foolish, intense, and usually short-lived passion or admiration.

Showing 1541–1560 of 3621 words.