For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
Not 'the' watchers & no place did I find it being used of fallen angels.
Of angels, yes a word sometime translated watcher is used in some places.
For instance in Daniel:
The sentence is by the decree of the watchers, the decision by the word of the holy ones, to the end that the living may know that the Most High rules the kingdom of men and gives it to whom he will and sets over it the lowliest of men.’ Daniel 4:17 (ESV)
17 "'The decision is announced by messengers, the holy ones declare the verdict, ... Daniel 4:17 (NIV)
17 "This sentence is by the decree of the angelic watchers And the decision is a command of the holy ones,..." Daniel 4:17 (NASB)
17 This word is by decree of the observers; the matter is a command from the holy ones.... Daniel 4:17 (HCSB)
Observer, watcher, messenger - the word is Strongs #5894 if you want to look it up-- "(Chaldee); from a root corresponding to (`uwr); a watcher, i.e. an angel (as guardian) :- watcher. Strong's Greek & Hebrew Dictionary."
This is not to in any way be confused with the 'version' of 'the watchers' in the movie Noah which has nothing to do with anything biblical other than the character's name & him being in a flood similar to the one in the Bible.
No! The Bible only says that they are "fallen" that is it.