These are more of ideas to help your brain invent something less chessy...
Erosion is like corrosion, with no acid.
Erosion happens 'cuz the surface get frozen and beaten by the ocean. (they kinda rhyme) :)
Erosion is the transportation of, the deportation...
~OR~
I cant think of anything for weathering but i got something good, but its still cheesy/ ):
Erosions' got the grooves and so it moves. But weathering breakdown and changes so its molecules changes.
I'm sorry these kinda suck...