Where does "grams" in "n-grams" come from?
< Ancient Greek γρ?μμα (grámma, "letter; something written"), used
both in Classical derivations (anagram, epigram, program) and in new
coinages (telegram). The specific sense of "word consisting of N
characters" is slightly post-Classical, first attested in monogram (<
Latin monogrammum < Byzantine Greek μον?γραμμον), but productive in
English: bigram, trigram, tetragram (~=tetragrammaton), pentagram,
etc.
Quoted from Corpora List
< Ancient Greek γρ?μμα (grámma, "letter; something written"), used
both in Classical derivations (anagram, epigram, program) and in new
coinages (telegram). The specific sense of "word consisting of N
characters" is slightly post-Classical, first attested in monogram (<
Latin monogrammum < Byzantine Greek μον?γραμμον), but productive in
English: bigram, trigram, tetragram (~=tetragrammaton), pentagram,
etc.
Quoted from Corpora List