Augury (4)
'augury' is the definition.
(omen is a kind of augury)
This is all the clue.
(Other definitions for omen that I've seen before include "Harbinger, augury" , "Augury, portent" , "Portent, prophetic indicator" , "Gloomy sign" , "Prognostication" .)
'augury' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sign that I've seen before include "Engage by written agreement" , "Public notice; portent" , "Notice; symbol" , "Mark" , "house" .)