Himalaya or Himalayas?
Himalaya or Himalayas? Applying the word "Himalayas" to the Himalayan mountains is a piece of linguistic butchery that became popular in the last century and now seems to be in decline. Its origin appears to lie in the European fondness for pluralising mountains - the Alps, the Andes, the Apennines etc - coupled with a failure to appreciate that the correct plural of "Himalaya" is "Himalaya," just as the correct plural for the English word "sheep" happens to be "sheep."
The word Himalaya is derived from the Sanskrit words" Hi-ma" - snow, and "a-la-ya" - abode. There's no need for a plural, but if a plural is for some reason preferred ("abodes of snow") the rules of Sanskrit and other Indian languages indicate that the word should remain unchanged.
The word Himalaya occurs frequently as a geographical term in the Mahabharata, although translators haven't been shy of using the bastardised plural form in English versions.
The Greek geographer Megasthenes perhaps encountered the word, or something like it, in the fourth century BCE. In his Indica (pdf document) he says that "Hemodos" and "Himaos" were amongst the names applied by natives to the mountains marking the northern boundary of India. The 10th century Persian scholar Alberuni gives Himavant (or Himavat) - also the name of a Hindu god - as the name of India's northern mountains. Close relatives of the name "Himalaya" - "Himal", "Himalay", "Himaliya" - seem to be firmly established in various Indian languages.
The 1911 edition of the Encylopedia Britannica uses "Himalaya" as the title for its article about the mountains. The usage was perhaps not quite universal at that time, since the plural form appears (once) in the article and also in the title of one of the references cited (a book published in 1891). And the plural form appears in various other articles in the same edition of the Encylopedia. An article on the word "Himalaya" published in the Himalayan Journal in 1929 makes no mention at all of "Himalayas." But the pages of the journal are sprinkled over many decades with the plural form, and a fair proportion of the offending authors are Indian.
The explorer Eric Shipton, in his 1936 book Nanda Devi, uses "Himalaya" just about about exclusively. But Charles Houston, one of the members of the team that climbed Nanda Devi in 1936, refers repeatedly to the "Himalayas" in his 1999 introduction to a new edition of Shipton's book.
The current online edition of the Encylopedia Britannica - which has long outlived its traditional authority - has "Himalayas" as the title of its article about the mountains. Wikipedia has stuck with the same approach, prompting a lively debate on its discussion page. Both now look a little dated.
"Himalaya" isn't the only Indian word to have colonised the English language only to be subjected to English usage and English-style pluralisation. There are chapatis, popadoms, swamis, gurus and jawans. So why not Himalayas?
All the same, current trends appear to favour the word "Himalaya" over "Himalayas." There is an overwhelming preference for it in recent scholarly and scientific works, and many mountaineers and travellers have followed suit. Himalaya Masala more or less adheres to that convention.