Here is a list of nouns that start with INS.

insanity, inscription, inscrutability, insect, insecticide

insecurity, insemination, insert, insertion, inset

inside, insight, insignificance, insinuation, insistence

insolence, insomnia, insouciance, inspection, inspector

inspiration, instability, installation, installment, instance

instancy, instant, instigation, instigator, instillation

instinct, institute, institution, institutionalization, instruction

instructor, instrument, instrumentation, insubordination, insularity

insulation, insulator, insulin, insult, insurance

insurgence, insurrection

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