inconsistent
US /ˌɪn.kənˈsɪs.tənt/
UK /ˌɪn.kənˈsɪs.tənt/

1.
incoerente, incostante
not staying the same throughout, or not in agreement with something
:
•
His statements were inconsistent with the evidence.
Le sue dichiarazioni erano incoerenti con le prove.
•
The quality of the product has been inconsistent.
La qualità del prodotto è stata incostante.