There were giants Men so called partly for their high stature, but principally for their great strength and force, whereby they oppressed and tyrannised over others. For this is mentioned as another sin and cause of the flood.
Related Commentaries of Genesis 6:4
Genesis 6:4
4 There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.