If I haven't owned a home in 3 years, am I a first time home buyer ?

No.

If you have owned a home at any time after you were born, and you are buying a home now, you are not a first time home buyer.

 

It depends on what you are trying to do.  

 

For example, if you want to take money out of your IRA to buy a house and avoid the 10% early distribution penalty, your are a "first time home buyer".

 

"The definition of 'first-time home buyer' in this case is broader than you might think. You qualify as a first-time home buyer so long as you had no ownership interest in a main home any time within two-years before the date you acquire your new home."

Reference: https://www.nolo.com/legal-encyclopedia/using-ira-make-house-down-payment.html#:~:text=If%20you%20qualify%20as%20a,income%20tax%20on%20the%20withdrawal.