photo by Hatem Moushir
The plural of nilgai is also nilgai - or nilgais, which you say nill-guys, or, thrillingly, nilghau (you say it nillgaw) or nilghaus - are large Indian antelopes. That one in the picture is a male: it's easy to tell because it's grey, and the females are brown (and almost always have no horns).
Its scientific name is Boselaphus tragocamelus, which translates, more or less, as the cow-deer billygoat-camel; but then people have always been confused about nilgai. On the Indian subcontinent, where it lives, it's variously regarded as a cow, a divine creature, or vermin.
Okay, then, here's a question: the gai bit is Hindi for cow, but what does the nil bit mean, do you think?*
Word To Use Today: nilgai.
*No, not stripy-socks. No, not, white-tie, either. Here's a clue. What colour is it?
Yes, that's right, grey or brown, according to sex. So the answer to the question what does nil mean in Hindi? is, obviously...
Well, I said the thing was confusing.
The Hindu nīlgāw translates as blue bull, from the Sanskrit nīla, dark blue, plus go, which means bull.