It is often the case that a word is borrowed by several languages, and not just by one. Such words usually convey concepts, which are significant in the field of communication. Many of them are of Latin and Greek origin. Most names of sciences are international, e.g. philosophy, mathematics, physics, chemistry, biology, medicine, linguistics, lexicology. There are also numerous terms of art in this group: music, theatre, drama, tragedy, comedy, artist, primadonna.
It is quite natural that political terms frequently occur in the international group of borrowings: politics, policy, revolution, progress, democracy, communism, antimilitarism.
20th c. scientific and technological advances brought a great number of new international words: atomic, antibiotic, radio, television, sputnik. Sputnik is a Russian borrowing, and it became an international word (meaning a man-made satellite) in 1961, immediately after the first space flight by Gagarin.
The English language also contributed a considerable number of international words to world languages. Among them the sports terms occupy a prominent position: football, volleyball, baseball, hockey, cricket, rugby, tennis, golf, etc.
Fruits and foodstuffs imported from exotic countries often transport their names too and, being simultaneously imported to many countries, become international: coffee, cocoa, chocolate, coca-cola, banana, mango, avocado, grapefruit.
It is important to note that international words are mainly borrowings. The outward similarity of such words as the E. son, the Germ. Sohn and the R. сын should not lead one to the quite false conclusion that they are international words. They represent the Indo-European group of the native element in each respective language and are cognates, i. e. words of the same etymological root, and not borrowings.
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: history - story, fantasy - fancy, fanatic - fan, defence - fence, courtesy - curtsy, shadow - shade.