English Words Starting With I

• infielder

  nounC1
  /ˈɪnfiːldə(r)/A baseball or softball player whose defensive position is in the infield (the area of the field enclosed by the bases).
• infighting

  nounB2
  /ˈɪnfaɪtɪŋ/Hidden conflict, disagreement, or competition for power among members of the same group or organization.
• infill

  adjectivenounverb-transitiveC1
  /ˈɪnfɪl/To fill in a gap, hole, or empty space; material used to fill such a space.
• infiltrate

  nounverbverb-intransitiveverb-transitiveC1
  /ˈɪn.fɪl.treɪt/To secretly or gradually enter or gain access to a place, organisation, or system, especially with hostile intent or to obtain information.
• infiltration

  nounC1
  /ˌɪnfɪlˈtreɪʃən/The act of secretly or gradually entering or joining a group, place, or system, especially for military, espionage, or harmful purposes.
• infiltration capacity

  nounC1
  /ˌɪnfɪlˈtreɪʃən kəˈpæsəti/The maximum rate at which water can enter soil or porous material under given conditions.
• infiltration gallery

  nounVery Low
  /ˌɪnfɪlˈtreɪʃən ˌɡæləri/A horizontal or slightly inclined underground tunnel, typically built into a hillside or riverbank, designed to collect groundwater or water seeping through soil/rock by gravity.
• infiltrator

  nounC1
  /ˈɪnfɪltreɪtə(r)/A person who secretly and gradually enters an organization, group, or place, typically to gain secret information or to undermine it.
• infiltrometer

  nounC2
  /ˌɪnfɪlˈtrɒmɪtə/A device used to measure the rate at which water enters soil or porous media.
• infimum

  nounVery Low
  /ˈɪnfɪməm/In mathematics, the greatest element that is less than or equal to all elements of a given set.
• infinite

  adjectivenounC1
  /ˈɪnfɪnət/Having no limits, boundaries, or end; extending indefinitely.
• infinite baffle

  nounLow/Very Low
  /ˈɪnfɪnət ˈbæfəl/A loudspeaker enclosure design where the speaker is mounted in a sealed box, separating the front and rear sound waves to prevent acoustic cancellation.
• infinite decimal

  nounC1
  /ˈɪnfɪnət ˈdɛsɪml/A decimal representation of a number that continues indefinitely without terminating.
• infinite product

  nounC2
  /ˈɪnfɪnət ˈprɒdʌkt/A mathematical expression representing the product of an infinite sequence of terms.
• infinite regress

  nounC2
  /ˌɪnfɪnət ˈriːɡres/A sequence of reasoning or justification that can never come to an end; each step requires justification by a further step, ad infinitum.
• infinite series

  nounC1/C2
  /ˌɪnfɪnət ˈsɪəriːz/In mathematics, a sum of an infinite number of terms.
• infinitesimal

  adjectivenounC1
  /ˌɪn.fɪ.nɪˈtes.ɪ.məl/Extremely small; so small as to be negligible or almost impossible to measure.
• infinitesimal calculus

  nounC1
  /ˌɪn.fɪ.nɪˈtes.ɪ.məl ˈkæl.kjə.ləs/The branch of mathematics that deals with rates of change (differentiation) and accumulation of quantities (integration), operating with infinitely small quantities.
• infinitive

  adjectivenounC1
  /ɪnˈfɪnɪtɪv/The base form of a verb, typically preceded by 'to' (e.g., to go, to see), that expresses the action or state without reference to person, number, or tense.
• infinitive clause

  nounC1
  /ɪnˈfɪn.ɪ.tɪv klɔːz/A grammatical structure where an infinitive verb (e.g., 'to go', 'to see') functions as the main verb of a subordinate clause.

Showing 1601–1620 of 3621 words.