Thank you. I thought it must be but it is not in chambers unless I am looking in the wrong place. I think this gives Ariel for 30 across. And how do you parse "Rootle" for 9 down "Footballer could get flab with this grub".
Sorry, Bozzer - it's my misreading of the dictionary that's at fault! Your 'rooty' and suggestion of 'rootier' as the comparative was right - I'd just zoomed in on 'rootier' actually being shown in my dictionary.