World Wide Words has a reasonable description of the word tiffin's origin.

More than any other word, tiffin, meaning lunch or any light meal, evokes British India.

 

It entered the language at the very beginning of the nineteenth century, perhaps because the English fashion for eating dinner mid-afternoon was giving way under the influence of the Indian climate to a main meal taken later in the day, requiring a lighter midday meal and a name for it. Why the much older luncheon wasn’t used isn’t clear. Instead, the English in India borrowed tiffing, an old English dialect or slang word for taking a little drink or sip. (I forbear from suggesting that the habit among some sahibs of drinking their lunch had something to do with the popularity of the term.) The word is still widely used in India for any hot light meal or snack taken at any time during the day.

 

In Mumbai (formerly Bombay), the term tiffin-wallah is sometimes heard, though the more common term is dabbawallah. Lunches are cooked at home by workers’ wives and then transported, often by train, perhaps 20 or 30 miles to their husbands' workplaces, each three-tiered tiffin-carrier or dabba probably passing through several hands in a sophisticated and efficient cooperative process. Those who deliver the meals by bicycle on the final stage of their journeys are the tiffin-wallahs or dabbawallahs.

 

An early example of tiffin is from a guide book, Cordiner’s Ceylon, of 1808: “Many persons are in the habit of sitting down to a repast at one o’clock, which is called tiffen, and is in fact an early dinner”.

World Wide Words has a reasonable description of the word tiffin's origin.

More than any other word, tiffin, meaning lunch or any light meal, evokes British India.

It entered the language at the very beginning of the nineteenth century, perhaps because the English fashion for eating dinner mid-afternoon was giving way under the influence of the Indian climate to a main meal taken later in the day, requiring a lighter midday meal and a name for it. Why the much older luncheon wasn’t used isn’t clear. Instead, the English in India borrowed tiffing, an old English dialect or slang word for taking a little drink or sip. (I forbear from suggesting that the habit among some sahibs of drinking their lunch had something to do with the popularity of the term.) The word is still widely used in India for any hot light meal or snack taken at any time during the day.

In Mumbai (formerly Bombay), the term tiffin-wallah is sometimes heard, though the more common term is dabbawallah. Lunches are cooked at home by workers’ wives and then transported, often by train, perhaps 20 or 30 miles to their husbands' workplaces, each three-tiered tiffin-carrier or dabba probably passing through several hands in a sophisticated and efficient cooperative process. Those who deliver the meals by bicycle on the final stage of their journeys are the tiffin-wallahs or dabbawallahs.

An early example of tiffin is from a guide book, Cordiner’s Ceylon, of 1808: “Many persons are in the habit of sitting down to a repast at one o’clock, which is called tiffen, and is in fact an early dinner”.

This site has a reasonable description of the word's origin.

More than any other word, tiffin, meaning lunch or any light meal, evokes British India.

It entered the language at the very beginning of the nineteenth century, perhaps because the English fashion for eating dinner mid-afternoon was giving way under the influence of the Indian climate to a main meal taken later in the day, requiring a lighter midday meal and a name for it. Why the much older luncheon wasn’t used isn’t clear. Instead, the English in India borrowed tiffing, an old English dialect or slang word for taking a little drink or sip. (I forbear from suggesting that the habit among some sahibs of drinking their lunch had something to do with the popularity of the term.) The word is still widely used in India for any hot light meal or snack taken at any time during the day.

In Mumbai (formerly Bombay), the term tiffin-wallah is sometimes heard, though the more common term is dabbawallah. Lunches are cooked at home by workers’ wives and then transported, often by train, perhaps 20 or 30 miles to their husbands' workplaces, each three-tiered tiffin-carrier or dabba probably passing through several hands in a sophisticated and efficient cooperative process. Those who deliver the meals by bicycle on the final stage of their journeys are the tiffin-wallahs or dabbawallahs.

An early example of tiffin is from a guide book, Cordiner’s Ceylon, of 1808: “Many persons are in the habit of sitting down to a repast at one o’clock, which is called tiffen, and is in fact an early dinner”.

World Wide Words has a reasonable description of the word tiffin's origin.

More than any other word, tiffin, meaning lunch or any light meal, evokes British India.

It entered the language at the very beginning of the nineteenth century, perhaps because the English fashion for eating dinner mid-afternoon was giving way under the influence of the Indian climate to a main meal taken later in the day, requiring a lighter midday meal and a name for it. Why the much older luncheon wasn’t used isn’t clear. Instead, the English in India borrowed tiffing, an old English dialect or slang word for taking a little drink or sip. (I forbear from suggesting that the habit among some sahibs of drinking their lunch had something to do with the popularity of the term.) The word is still widely used in India for any hot light meal or snack taken at any time during the day.

In Mumbai (formerly Bombay), the term tiffin-wallah is sometimes heard, though the more common term is dabbawallah. Lunches are cooked at home by workers’ wives and then transported, often by train, perhaps 20 or 30 miles to their husbands' workplaces, each three-tiered tiffin-carrier or dabba probably passing through several hands in a sophisticated and efficient cooperative process. Those who deliver the meals by bicycle on the final stage of their journeys are the tiffin-wallahs or dabbawallahs.

An early example of tiffin is from a guide book, Cordiner’s Ceylon, of 1808: “Many persons are in the habit of sitting down to a repast at one o’clock, which is called tiffen, and is in fact an early dinner”.