APP, I'd never seen or heard the word at 9 A! It's definitely an odd one, but the clue does lead to it..
A four letter word for 'Walk', take steps etc, with the usual 'that is' and the common 'certainly' (yes, agreed etc) inside.
App, thanks - and glad I could help. Yes, it could be a bit of a challenge having a new setter to get used to - it'll make us work a little harder, I expect!