The word "inchoate" means "unripe" or "undeveloped." Knowing this helps us know what in inchoate offense is. It is a crime that comes about because the offender wants to commit the crime, even though the crime never actually happens. It is "inchoate" because it never actually develops into a more conventional crime.
Inchoate offenses fall into three categories. There is attempt, conspiracy, and solicitation. In each case, the crime need not be committed. It is an inchoate offense to attempt to commit a crime, to plot with others to commit a crime, or to try to get someone else to commit a crime for you.