Publicity man starts to lie in inquiry (5)
I believe the answer is:
probe
'inquiry' is the definition.
(I know that probe is a type of inquiry)
'publicity man starts to lie in' is the wordplay.
'publicity' becomes 'pr' (abbreviation for public relations).
'man' becomes 'Ed' (short for Edward).
'starts' means to remove the last letter.
'to' means one lot of letters go next to another (I've seen this in other clues).
'lie in' becomes 'ob' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ed' with its final letter removed is 'e'.
'e' after 'ob' is 'obe'.
'pr'+'obe'='PROBE'
Can you help me to learn more?
(Other definitions for probe that I've seen before include "Intrusive device" , "sound" , "Question or examine closely" , "Poke into" , "Examine searchingly" .)