Investigates publication's top dresses (6)
I believe the answer is:
probes
'investigates' is the definition.
(probing is a kind of investigating)
'publication's top dresses' is the wordplay.
'publication's top' becomes 'p' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'dresses' becomes 'robes' (robing is a kind of dressing).
'p'+'robes'='PROBES'
Can you help me to learn more?
(Other definitions for probes that I've seen before include "Examines in depth as dentist does tooth" , "Examines as dentist does decaying tooth" , "Conducts penetrating investigation" , "Examines carefully as dentist does a bad tooth" , "Investigates as dentist does tooth" .)