The term “annualize” means to project a yearly outcome on the basis of the current performance. The annualized return is just an extrapolated data of the particular tenure that is mentioned.

For example, if a particular asset has given a return of 5% in a period of 3 months, then the annualized return is 20%.

It is calculated as:
(Current Return/ Time period in which the mentioned returns have been achieved) * 12.