Touches inside of trachea, but softly (5)
I believe the answer is:
abuts
'touches' is the definition.
(abutting is a kind of touching)
'of trachea but softly' is the wordplay.
'of' indicates a hidden word.
'ABUTS' is hidden within 'trachea but softly'.
'inside' acts as a link.
(Other definitions for abuts that I've seen before include "Lies adjacent to another" , "Ends or leans against" , "borders" , "Touches, leans on" , "Of building, is next to" .)