trender

noun3

1. •
   Something which trends (has a tendency to go) in a certain way.

   • The computer can ferret out slow-movers, down-trenders, and nonstandards, which leads to simplification and higher turnover. — 1965
2. •
   (rare) Someone who is trendy, who sets or follows trends.
3. •
   (dialect, no longer used) One who cleans the filth from wool.