As Chouette says, it's a verb, and it means "to have".
The conjugation in present tense is like this:
io ho I have
tu hai you have
lui,lei,Lei* ha he/she/You* have
noi abbiamo we have
voi avete you have
loro,Loro* hanno they/You* have
I hope this helps you a little =),
* These forms are used to older people,
in order to be polite.