Definition - What does Grand Theft mean?
Grand theft is the illegal stealing of another person's property where the property has a value over a certain amount. Grand theft is a serious form of theft. Petty theft, an alternate type of theft, is theft of property that has a much smaller value. For example, petty theft would be stealing candy from a candy store. Grand theft would be stealing hundreds of thousands of dollars worth of diamonds from a jewelry store.
Justipedia explains Grand Theft
Just like many other crimes, theft has varying levels of severity. Grand theft is a more severe level of theft, and it can come with severe punishments. Lengthy jail sentences can accompany those who are convicted of grand theft. When an automobile is stolen, it is can also be grand theft. In such cases, it is the expensive nature of cars that qualify these thefts as grand.