Says they smell, for example! (5)
I believe the answer is:
sense
'smell for example' is the definition.
(I know that olfaction is a type of modality)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for sense that I've seen before include "Meaning - feeling" , "eg Taste, smell" , "Purport" , "Faculty of perception" , "Suspect" .)