wide
濶 centers on broadness or spaciousness: something wide, open, or expansive.
濶 is a variant form of 闊, combining 氵 (water) with a component that likely contributed the sound and the idea of width or openness. The exact historical development of the right side is uncertain.
Water 氵 spreads out wide, and the right side looks like a gate 門 with a tongue 舌 inside, as if the tongue is wagging wide open.
For カツ, imagine a wide river cutting through a valley: cut -> カツ, and the water spreads wide.