iatr- or iatro- [from Greek iatros physician] Pertaining to medicine or physicians (iatric, iatrology).

ichn- or ichno- [from Greek ichnos track, trace, footprint] Denotes a footprint, trace, or track of an organism (ichnite, ichnology).

ichthy- or ichthyo- [from Greek ichthys fish] Fish or fishlike (ichthyic, ichthyology).

icos- or icosa- or icoso- [from Greek eikosi twenty] Twenty (icosahedron).

icter- or ictero- [from Greek icteros jaundice] Jaundice, jaundicelike, yellow (icterohematuria, icteritious).

idio- [from Greek idios individual] Specific to a particular individual, organ or tissue (idioretinal).

ile- or ileo- [Latin ileum from Greek eilein to twist] Ileum (ileocecal valve).

im- or in- [from Latin im-, in-] (1) in, into, inward (incise); (2) not (impotent, incontinence); (3) to cause to become (impregnate).

immun- or immuno- [from Latin immunis exempt, immune] immune, safe; immunity, confering immunity (immunotherapy).

infra- [Latin infra below, on the under side, lower than, further along; to the south] Below, lower than (infraorbital, infraclass).

inter- [Latin inter between, among, during] Between, among, during (interleukin).

intra- or intro- [Latin intra, intro- within, inside, during, under] Among, within, inside, during (intramuscular, introgression).

iod- or iodo- Denotes iodine (iodophilia).

irid- or irido- [from Greek iris, irid- iris] Pertaining to the iris (irideremia).

ischio- [from Greek ischion hip] Pertaining to the ischium (ischiopubiotomy).

ischo- [from Greek ischein to restrain] Denotes suppression or restraint (ischochymia).

iso- [from Greek isos equal] Equal (isopathy).

japon- Refers to Japan (Andrias japonicus).

jav- or java- Refers to Java (Javanthropus).

jejun- or jejuno- [from Latin jejunum fasting, hungry] Pertaining to the jejunum (jejunectomy).

juba- [from Latin juba mane, crest (of a helmet)] (1) rested (Neochen jubata, Ptarmus jubatus) (2) maned (Acinonyx jubatus, Chrysocyon jubatus).

juxta- [Latin juxta near, next to] Near, alongside (juxtapyloric).