Definition of "onsetter"

onsetter¹

noun
plural onsetters
1. (mining, historical, UK, dialect, Northern England) A worker at the bottom of a mineshaft who exchanges the empty and full corves.

onsetter²

noun
plural onsetters
1. (medicine) One who undergoes the onset of a condition.
  Quotations
  Compared to normative stayers, increasing hyperactivity and maltreatment during childhood were associated with a likelihood of being a late onsetter.
  2008, Anna Hyun, Factors Associated with Stability and Change in Offending Among School Enrolled Adolescents and Their Transitions into Emerging Adulthood