"Yikes!" (4)
'yikes' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for egad that I've seen before include "Mild oath (archaic)" , "Old oath" , "traditional oath" , "Mild oath - aged (anag)" , "My word once" .)
(Other definitions for eek that I've seen before include "Yikes! Oo-er!" , "fearful cry" , "Cry of alarm" , "Expression of surprise" , "I'm frightened!" .)