The words shirt and skirt etymologically descend from the same root. Shirt is a native word, and skirt (as the initial sk suggests), is a Scandinavian borrowing. Their phonemic shape is different, and yet there is a certain resemblance which reflects their common origin. Their meanings are also different but easily associated: they both denote articles of clothing.
Such words as these two originating from the same etymological source, but differing in phonemic shape and in meaning are called etymological doublets.
They may enter the vocabulary by different routes. Some of these pairs, like shirt and skirt, consist of a native word and a borrowed word: shrew, n. (E.) — screw, n. (Sc.).
Others are represented by two borrowings from different languages which are historically descended from the same root: senior (Lat.) — sir (Fr.), canal (Lat.) — channel (Fr.), captain (Lat.) — chieftan (Fr.).
Still others were borrowed from the same language twice, but in different periods: corpse [ko:ps] (Norm. Fr.) — corps [ko:] (Par. Fr.), travel (Norm. Fr.) — travail (Par. Fr.), cavalry (Norm. Fr.) — chivalry (Par. Fr.), gaol (Norm. Fr.) — jail (Par. Fr.).
Etymological triplets (i. e. groups of three words of common root) occur rarer, but here are at least two examples: hospital (Lat.) — hostel (Norm. Fr.) — hotel (Par. Fr.), to capture (Lat.) — to catch (Norm. Fr.) — to chase (Par. Fr.).
A doublet may also consist of a shortened word and the one from which it was derived (see Ch. 6 for a description of shortening as a type of word-building): history — story, fantasy — fancy, fanatic — fan, defence — fence, courtesy — curtsy, shadow — shade.