- Fic with less than 100 words: 'nanofic'
- For a fic with a multiple of 50 words, several variations on the term "drabble" can be used:
- 50 words: 'half-drabble' or 'semidrabble'
- 150 words: 'drabble-and-a-half' or 'sesquidrabble'
- 200 words: 'double-drabble' or 'droubble'
- 300 words: 'triple-drabble' or 'trabble'
- Any fic under 500 words: 'flash fiction' or 'flashfic'
- Any fic over 500 words but under 1000: 'short-short' (used mainly in professional work)
- Any fic under 1000 words: 'ficlet' (used more in fanfiction communities and amoung Net-based writers)
- Any fic over 100 words up to about 20 000: 'short story', or simply 'fic'
Anything over 20 000, and we're approaching novella territory, but if a fic is approaching novella territory it's unlikely to be mislabelled.
"Flashfic" in particular is an excellent term that should see more usage. Most fics that are mislabelled "drabbles" are actually flashfic.
(This list was derived in part from this discussion on Fanthropology and this article.)