A word from the Cantonese language that is pronounced as "la". This word is often (not always) used in every day conversations at the end of sentences. Usually Cantonese speakers also use this "la" word on online chat even when they are talking in English. The purpose is just to juice up their sentences and to make their sentences sound more Chinese. I'd like to point out again that not ALL sentences (English and Cantonese) can end with "la". Sometimes people spell the word as "lar" instead of "la", but both mean the same thing. There are also "lor", "meh", "ga bor", etc., that can also be put at the end of certain sentences.
A: "I'm leaving soon la."
B: "Why so soon ah? Dinner won't end in another 2 hours ga wor."
A: "I have another dinner that I need to attend to ah ma."
B: "OK la gum."