- incongruous
 - inglenook
 - imperium
 - indian tobacco
 - inkblot test
 - inspirit
 - intoxicatedness
 - invigoration
 - irrepressibility
 - interreflection
 - internality
 - interstitial emphysema
 - indigestibility
 - indigestibleness
 - in disguise
 - impassive
 - inexpressively
 - inefficiently
 - improvisation
 - interpretable
 - inexplicitness
 - isometropia
 - inferior rectus
 - inferior rectus muscle
 - introversion
 - inordinateness
 - imperious
 - Insectivora
 - Insessores
 - involution of uterus
 - interventricular artery
 - interventricular heart block
 - intervenous
 - interventricular sulcus
 - intervenous tubercle
 - intermediation
 - iodothyronine
 - iodotyrosine
 - iodoacetic acid
 - isoleucine
 - impregnation
 - incorporation
 - incoherent talking (due to intoxication)
 - intimate apparel
 - ionic
 - ionic dialect
 - Irish
 - indefinite integral
 - inroad
 - iritis