Chou Collection, Upper Volume
Radical: Mouth (kǒu)
Zá
Kangxi stroke count: 9
Page 187, Entry 07
Ocean of Texts (Pianhai) indicates it is pronounced za. It is commonly used among the people to refer to oneself.
Also, Central Plains Phonology (Zhongzhou Yinyun) indicates it is pronounced cha. The meaning is the same.