Today's Parola del Giorno is transitive verb addensare, which means to thicken.
The past participle is addensato; avere is used in compound tenses.
See the verb used below:
Per preparare la besciamella bisogna cuocere gli ingredienti a fuoco basso di modo che il composto possa addensarsi.
In order to prepare the béchamel, one needs to cook the ingredients on a low heat so that the mixture can thicken.