NGSL stands for New General Service List (NGSL). It is a list of approximately 2,800 words which are especially useful for students who want to read general texts in English. Together with the 1,000 NAWL words, these 3,800 words allow learners to understand almost 95% of most English texts; these are nearly all the words learners will ever need (not bad if you consider there are more than 600,000 words in English!).