Impoverish
Make a area/ person poor
Impoverishment
The process of becoming poor
Impresario
A person who finances and organises concerts and plays
Impromptu
Without being planned 
Imprudent
Not Showing care for consequences
Inalienable
Not to be taken away or given away
Inauspicious (in us spishus)
Not conductive to success or unlucky
Inborn
Existing from birth
Incipient
Beginning to happen or developed from the initial starting point
Incisive
Clear thinking or good analysis
Incivilty 
Rude or unsociable speech
Inclement
Stormy or cloudy
Incorrigible
Not being able to be corrected
Inculpate
Accuse or blame
Indefatigable
Persisting tirelessly
Indemnify
Compensate someone for harm or loss