'The Watchers' are often discussed within the context of the Book of Enoch, usually in reference to the 200 Watchers who fell.. but Watchers are also mentioned in the Book of Daniel..
'I saw in the visions of my head upon my bed, and, behold, a watcher and an holy one came down from heaven;'
'This matter [is] by the decree of the watchers, and the demand by the word of the holy ones: to the intent that the living may know that the most High ruleth in the kingdom of men, and giveth it to whomsoever he will, and setteth up over it the basest of men.'
'And whereas the king saw a watcher and an holy one coming down from heaven..'
each of these 3 instances is translated from the Aramaic word 'iyr - pronounced "ēr"
Strong's H5894 - `iyr (Aramaic) - masculine noun - 1) waking, watchful, wakeful one, watcher, angel - used 3 times in the KJ: Dan.4:13,17,23
from a root corresponding to H5782 - 'uwr - 1) to rouse oneself, awake, awaken, incite