inconsistent

/ˌɪnkənˈsɪstənt/
adjective
  1. Not staying the same in behavior, quality, or opinions; changeable or unreliable.
    • His performance has been inconsistent this season, sometimes excellent and sometimes poor.
    • She is inconsistent about keeping her promises, which frustrates her friends.
    • The weather has been inconsistent, with sunny days followed by sudden storms.
  2. Not in agreement or harmony; contradictory.
    • It is inconsistent to say you care about the environment while littering.
    • His actions are inconsistent with his stated beliefs.
    • The two reports are inconsistent with each other regarding the cause of the fire.
  3. Containing elements that do not match or fit together logically.
    • The committee found the proposal inconsistent with the company's goals.
    • Her story was inconsistent, changing details each time she told it.
    • The data set is inconsistent because some numbers were recorded in different units.