India, July 28 -- "Stephen, his blood wooed by grace of language and gesture, blushed."

- James Joyce in Ulysses

Every generation is wooed by its own language. It falls for fresh words, gives inherited words new meanings, and discovers slogans and catchphrases that become the soundtrack of its youth.

If you wanted to hear Delhi's newest words in circulation, Jantar Mantar was recently the place to stand. Students had gathered beside the centuries-old solar observatory to protest paper leaks in competitive exams. The air was thick with contemporary slogans, many destined for Instagram, alongside words already entering Delhi's everyday speech.

Every decade, Delhi sounds a little different. A decade or two ago, college students called an...