Detect
'detect' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for espy that I've seen before include "Spot, notice" , "Discern" , "Spot at a distance" , "Perceive" , "See" .)
'detect' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for feel that I've seen before include "Sense or touch" , "Experience, perceive" , "Have sensation of" , "Be aware of - texture" , "Have a belief; touch" .)
'detect' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for spot that I've seen before include "Notice, see" , "Blob" , "Mark, dot" , "Observe - place" , "Notice - fictional puppy" .)
(Other definitions for discover that I've seen before include "Be the first to have sight or knowledge of" , "Make a new finding" , "Find during a search" , "Be the first to find or see" , "Be first to observe" .)
'detect' is the definition.
(I know that detect is a more specific form of the action sight)
This is the entire clue.
(Other definitions for perceive that I've seen before include "Apprehend - sense" , "Understand" , "Comprehend" , "Become aware of, notice" , "See" .)