The Heb. word tamim means without blemish, and is the technical word for bodily and physical perfection, and not moral.  Hence it is used of animals of sacrificial purity.  It is rendered without blemish in Ex. 12:5; 29:1.  Lev. 1:3, 10; 3:1, 6; 4:3, 23, 28, 32; 5:15, 18; 6:6; 9:2, 3; 14:10; 22:19; 23:12, 18.  Num. 6:14; 28:19, 31; 29:2, 8, 13, 20, 23, 29, 32, 36.  Ezek. 43:22, 23, 25; 45:18, 23; 46:4, 6, 13.

Without Spot.  Num. 19:2; 28:3, 9, 11; 29:17, 26.

Undefiled.  Ps. 119:1.

This shows that Gen. 6:9 does not speak of Noah's moral perfection, but tells us that he and his family alone had preserved their pedigree and kept it pure, in spite of the prevailing corruption brought about by the fallen angels.  See Ap. 23 and 25.