Investigation puts pressure on awful bore (5)
I believe the answer is:
probe
'investigation' is the definition.
(probe is a kind of investigation)
'pressure on awful bore' is the wordplay.
'pressure' becomes 'p' (abbreviation**).
'on' indicates putting letters inside.
'awful' is an anagram indicator.
'bore' anagrammed gives 'robe'.
'p' inserted within 'robe' is 'PROBE'.
'puts' is the link.
(Other definitions for probe that I've seen before include "Poke into" , "Question or examine closely" , "sound" , "Closely enquire into" , "Examine searchingly" .)