English
sequencer
From sequence + -er.
A compound of sequence + -er
Proto-Indo-European *sekʷ- ‘to follow’
…
Latin sequēns ‘following’
Late Latin sequentia ‘a following’
Old French sequence ‘a sequence of cards, answering verses’
Middle English sequence
English sequence
Today it means
noun Any device that activates or deactivates the components of a machine or system according to a preplanned sequence (as in a washing machine, or central heating system).
Language periods are conventional ranges, not dates for this word.
Etymograph / sequencer