English
rater
From rate (“to appraise”) + -er.
Formed from rate ‘to appraise’ + -er
Proto-Indo-European *h₂reh₁- ‘to think’
…
Latin prō ratā parte ‘according to a fixed part’
Medieval Latin rata
Old French rate
Middle English rate
English rate
Today it means
noun One who provides a rating or assessment.
Language periods are conventional ranges, not dates for this word.
Etymograph / rater