I as in …

Ice

Ice Cream

Iceberg

ID

Idea

Idiot

Igloo

Ignorance

Ill

Illegality

Imagination

Immaturity

Import

Impossible

Impression

Improvement

In Time

Incest

Inch

Increase

Indian

Infection

Infinite

Inflation

Information

Inge

Inger

Inheritance

Ink

Inmate

Insert

Inside

Installation

Instructor

Instrument

Intelligence

Intensive

Interest

Internet

Interrupt

Intervention

Interview

Invention

Investigation

Investment

Invisibility

Invite

Ion

IQ

Ir

Irish

Irishman

Iron

Iron Man

Irony

Isis

Island

ISN

Isolation

Issue

Italian

Ives