'Generation' in the Bible

And Jehovah saith to Noah, 'Come in, thou and all thy house, unto the ark, for thee I have seen righteous before Me in this generation;

and the fourth generation doth turn back hither, for the iniquity of the Amorite is not yet complete.'

and Joseph looketh on Ephraim's sons of the third generation; sons also of Machir, son of Manasseh, have been born on the knees of Joseph.