A tumor
Explanation:
A tumor is a group or mass of abnormal tissues formed by a group of abnormal cells.
According to the normal growth pattern of a cell, new cells formed age and die, and then get replaced by new cells.
In the case of tumor, this normal pattern is not observed and the cells do not die or get destroyed in the normal path. Due to this, many cells accumulate to form the tumor.
The tumor cells have the ability to grow and divide rapidly at an accelerated rate.
Tumors can be malignant and cancerous or non-malignant or benign .