iatr/o medical care geriatrics – medical care of the elderly; pediatrician – a doctor who treats children; podiatry – medical care for feet.

icon/o image icon – an (often religious) image, in modern usage a simplified graphic of high symbolic content; iconology – science of symbols and icons; iconoclast – someone who destroys religious images and traditional beliefs.

idio peculiar, personal, distinct idiomatic – Peculiar to a particular language; idiosyncracy – a physical or mental characteristic typical or a particular person; idiot – someone who is distinctly foolish or stupid.

il, in in, into illuminate – to give light to; innovation – a new idea, method, or device; inspection – the act of examining or reviewing.

ig, il, im, in, ir not, without illegal – not legal; impossible – not possible; inappropriate – not appropriate; irresponsible – not responsible.

imag likeness image – a likeness of someone; imaginative – able to think up new ideas or images; imagine – to form a picture or likeness in the mind.

infra beneath, below infrastructure – underlying framework of a system; infrared – below the regular light spectrum.

inter between, among, jointly international – involving two or more countries; intersection – place where roads come together; intercept – to stop or interrupt the course of.

intra, intro within, inside intrastate – existing in one state; intravenous – inside or into a vein; introvert – shy person who keeps within him/herself.

ir not irredeemable – not redeemable; irreformable – not reformable; irrational – not rational.

iso equal isobar – a line on a map connecting points of equal barometric pressure; isometric – having equality of measure; isothermal – having equal or constant temperature.