Cases of word usage

1) to cause (a person, achievement etc) to seem unimportant or of small value (belittle)

2) unnecessary nervous excitement, especially about unimportant things (fuss)

3) talking too much about unimportant things (garrulous)

4) accompanying but not forming a necessary part; small and comparatively unimportant (incidental)

5) to give too much time or attention (to something); complain about unimportant details; to annoy (a person) (niggle)

6) a person who pays too much attention to unimportant rules, e.g. in language (pedant)

7) too concerned with unimportant details (persnickety)

8) a person in an unimportant position, compared to others (underling)