Oxford Dictionary: unrestricted; enormous
Merriam-Webster: lacking any controls; not bounded by exceptions
Roget's Thesaurus: having no restrictions; without exception; absolute
Cambridge Advanced Learner's Dictionary: not limited; infinite
Sify Broadband Dictionary: 150 MB upload/download limit per day, beyond which there will be a reduction in validity of one day for every 25 MB of extra usage in that calendar day.
I realised this bitter fact after downloading 275 MB today, and finding 6 days chopped off my account. And the bottom feeders don't even have a warning asterisk (conditions apply or the likes) on their tariff chart! (they do now on their website, but definitely did not when I bought the pack. Well, even if they do, it still shouldn't be called "unlimited"?) It just says "Unlimited Family Pack - 256 kbps". Connectivity is pathetic and speed is "shared".
Now lets go deeper into how Sify defines a few more terms:
SHARED: You will never ever get the maximum speed of 256 kbps. If you get 128, thank your stars!
ALWAYS ON: You will be disconnected atleast 10 times in 10 minutes.
I have some really nice words to say about these daylight robbers. In fact, a list of words. READ ENTIRE LIST