'And some of the words are just gloriously descriptive. No wonder a poet like Philip wants to keep on the books "eye-server" - a hired hand who only works when his boss is looking; "wheelbarrow farmer" for a smallholder and "lumpy tums" for a children's bedtime dish of oatmeal and milk.'

That's from UK site and I'd guess the tum refers to the tummy and the lumpy refers to the oatmeal which adds lumps to the stomach. I'd guess it took the place of milk and cookies today in many places.