Etymological doublets
Features:
a) may enter by different routes: shirt (native) - skirt (Scandinavian)
b) may be 2 borrowings from different languages which are historically descended from the same language: canal (Lat.) - channel (Fr.).
c) may be borrowed from the same language twice in different periods: gaol (Norm. Fr.) - jail (Paris. Fr.).
d) may later occur as etymological triplets: hospital (Lat.) - hostel (Norm. Fr.) - hotel (Paris. Fr.)
e) may consist of a shortened word and of the one from which it was derived: history - story, shadow - shade, fanatic - fan
f) may reoccur as borrowings
English pioneer > Russian "first" > English "пионер"
according to the way by which the word was borrowed
oral VS written direct VS indirect
Aboriginal words Parisian French words Latin>English
(through Fr. literature), Greek> Latin> English - via other language
Russian words of the 19 th c.