1) smaller or less important (than others); a person not yet legally of age (under 18 in GB) (minor)

2) to cause (a person, event etc) to seem less important or obvious (overshadow)

3) coming after the first; less important or less strong (secondary)

4) (a person who is) lower in rank or position; to consider or treat (a person, one's own wishes) as less important (subordinate)