repetitor
A private instructor in a repetitorium.
There is probably not a class throughout the Russian Empire, there is certainly not a gymnasium or a real-school, in which a certain proportion of the pupils do not avail themselves of the services of a repetitor ; and in the case of the lower classes of some schools every second or third pupil does so.
Someone or something that repeats something.
For the repetitor, its self-similarity ratio r is 1/3, identifying the subdivision of the original line into three pieces.
Where it comes from
Compare Latin repetitor (“a reclaimer”).
Adapted from the Wiktionary entry repetitor (CC BY-SA 4.0).