Lack of the knowledge gained from experience.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "inexperience" in a sentence
"An executive summary of the report, released on Wednesday, repeatedly emphasized what it described as the inexperience, confusion and limited expertise of staff assigned to at least six investigations involving Madoff since 1992."
"Obama 's lack of leadership and inexperience is going to ruin this once so proud and beautiful country."
"His inexperience is showing and it will get worse."