sudden death    This expression should be familiar to sports fans.  In football, for example, when the match remains undecided even after extra time and penalty shoot outs each side lines up its best shooters to take a shot at the goal, in alternate order. Whoever scores the first goal wins the match. It is sudden death for the other team. The practice is found in hockey also.
The phrase had a more literal (and gruesome) meaning in earlier days.  In colonial India, when an officer entered a Dawk Bungalow ( I have written this word as given in Hobson-Jobson), the standing dish was a fowl caught in the yard even as the officer entered the compound, killed and served as a spatchcock.  It was sudden death for the fowl. (A spatchcock, I find, is a dish where the fowl is split, stuffed and grilled. A pure vegetarian, I have no knowledge of these matters.  I am only recording the meaning as given in standard dictionaries.)
Incidentally the TB of today was the Dawk Bungalow of those days.  Mail was carried by a relay of runners who needed places to rest in the course of their duty. Because they carried ‘dawk’ (=mail) the bungalows were called Dawk Bungalows.

grass widow Long before the expression appeared in colonial India, it was  current in the European languages where, generally, it signified a married (and deserted) woman of easy virtue; or an unmarried mother (the barnyard grass substituting for the marriage bed).
As used in colonial India, it had none of the lewd associations suggested above. It merely referred to the wives of the English officers who, in summer, would retreat to the cool hill stations while their husbands slogged at their work in their offices, in the sweltering heat of the plains. The expression today has the more generalised meaning of ‘a woman whose husband is away often or for a prolonged period’
sitting up.  A social event. I cannot do better than quote from a contemporary source cited in Hobson–Jobson.  ‘When a young lady arrives in Madras, she must, in a few days afterwards sit up, to receive company, attended by some beau or master of the ceremonies, which perhaps, continues for a week, or until she has seen all the fair sex and gentlemen of the settlement.’  The event would generally take place ‘at the house of some lady of rank or fortune’.

chit/chitty    Now rarely encountered in Indian English, and found, almost exclusively in the local languages. But it was very much in use in colonial India and survives even today in Standard English.
Chit has been defined as ‘a letter or a note; also a certificate given to a servant or the like.’ That was the meaning in those days.  Today you may send a note to your friend to pay the bearer Rs 20 (or whatever). In those days the English in India would send a chit or chitty.
As for its use today the COD has this: ‘a short official note, memorandum or voucher, typically recording a sum owed.’

Tiffin   The English first encountered this word in the then Madras city.  It signified the midday meal. Here is a quote from an 1812 publication: ‘ the dinner is scarcely touché, as every one eats a hearty meal called tiffin at 2 o’clock.’ Another source of about the same date has this:’…he insists on your taking tiffin; and such a tiffin!’  The English corresponding term is luncheon but how meagre a shadow is the European meal to its glowing Asiatic cousin!’
In Mysore among rickshaw drivers (and earlier, jatkawalahs) tiffin is breakfast. (But nashta is equally popular.)

Factory/President/Presidency
In the British days we had the Presidencies of Bombay. Madras and Calcutta. But the chief executive officer was Governor, not President.  How come?
A factory in the colonial days was a trading post. The East India Company established such ‘factories’ all along the coastline of India. The chief executive officer of these factories was a President.  In course of time the trading posts were abolished and the East India Company wound up.  But the ‘Presidents, with vastly enlarged powers, continued.  They became  Governors, and their territorial jurisdiction, a Presidency.
Maxims and observations of Kay S Wye
A government job in India, that is, Bharath, is a licence to fleece the public.

(The author can be contacted at ksyadurajan@yahoo.com)