Pedestrian is an ordinary chap (3-2-3-6)
I believe the answer is:
man-in-the-street
'pedestrian' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'an ordinary chap' is the wordplay.
I cannot really see how this works, but
'an' could be 'i' (Roman numeral for one) and 'i' is located in the answer.
'chap' could be 'man' (chap can mean a man) and 'man' is located in the answer.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Another definition for man-in-the-street that I've seen is " Tom, Dick or Harry".)