Some claim pedestrians cause an obstruction (6)
I believe the answer is:
impede
'some claim pedestrians cause an obstruction' is the definition.
I can't judge whether this defines the answer.
'some claim pedestrians cause' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'IMPEDE' is hidden in the letters of 'claim pedestrians cause'.
Can you help me to learn more?
(Other definitions for impede that I've seen before include "Delay, be an obstacle" , "Slow" , "Block progress of (something)" , "Hinder or obstruct, say progress" , "Delay progress of (something)" .)