Distrustful person (5)
I believe the answer is:
cynic
'distrustful person' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cynic that I've seen before include "Person who sneers at others, a sceptic" , "One believing the worst" , "One who believes people's motives are always selfish" , "One who thinks only self-interest motivates people" , "Pessimistic viewer of human motives" .)