What does I stand for?

Indenter

In hardness testing, a solid body of prescribed geometry, usually chosen for its high hardness, that is used to determine the resistance of a solid surface to penetration. 

Inflame

Inaccuracy

The difference between the input quantity applied to a measuring instrument and the output quantity indicated by the instrument. The inaccuracy of an instrument is equal to the sum of its instrument error and its uncertainty.

Icing

Icing caused by freezing sea spray or snow forming a layer of ice on deck and superstructure when operating in low temperatures may have major impact on the safety and general operation of a vessel.

Instructor

A person who gives information or knowledge, usually in a formal setting such as a lesson or briefing

Inaccurate

Inactive

Not switched on, in a passive state.

Inchon

Incident

An event or happening which interrupts normal procedure.

Incisor