It's just a comparative adjective...
Posted by Alex on November 28, 2001
In Reply to: The word junior posted by Bruce Kahl on November 27, 2001
: : I'd like to know the meaning of the word 'junior' in the following sentence:
: : "He married with a girl who was twenty years his 'junior'.
: : Junior in this case is not his younger son, once he married in an advanced age, and never had had son.
: It means the girl was twenty years younger than he.
: If she is 20 years his junior and he is 50 years old then she is 30 years old.
positive comparative superlative
iuvenis (young) iuvenior
senex (old) senior
bonus (good) melior
melior then gives us words like 'ameliorate'
- to make better.
so anyway junior just seems to be a corruption of iuvenior. the confusion of the original point comes from the fact that these adjectives when used on their own take on substantive properties.