in·con·sis·tent 
/ˌɪnkənˈsɪstənt/ adjective
/ˌɪnkənˈsɪstənt/ adjective [more inconsistent; most inconsistent] : not consistent: such as a : not always acting or behaving in the same way
▪ His pitching has been very inconsistent. [=unreliable] ▪ Customers have been complaining about the inconsistent service they have received.
b : not continuing to happen or develop in the same way
▪ The pain has been inconsistent. ▪ Her grades have been inconsistent this school year.
c : having parts that disagree with each other
▪ Their descriptions of the accident were inconsistent. ▪ The results of the two experiments were inconsistent. ▪ She was inconsistent in her argument. [=her argument included parts that did not agree with one another] : not in agreement with something ▪ His statements were inconsistent with the truth. [=were not true] ▪ The decision was inconsistent with the company's policy.
▪ His pitching has been very inconsistent. [=unreliable] ▪ Customers have been complaining about the inconsistent service they have received.
b : not continuing to happen or develop in the same way
▪ The pain has been inconsistent. ▪ Her grades have been inconsistent this school year.
c : having parts that disagree with each other
▪ Their descriptions of the accident were inconsistent. ▪ The results of the two experiments were inconsistent. ▪ She was inconsistent in her argument. [=her argument included parts that did not agree with one another] : not in agreement with something ▪ His statements were inconsistent with the truth. [=were not true] ▪ The decision was inconsistent with the company's policy.
— in·con·sis·tent·ly adverb
▪ The team has been playing inconsistently all season.
▪ The team has been playing inconsistently all season.
