viŝi

The base that forviŝi was waiting for. When forviŝi came up at rank 2062 it had to be introduced without its own root, because viŝ- sat outside the list. That is the wrong way round pedagogically and it happens whenever the compound is the commoner word in print. Here is the base at last: viŝi is the plain physical act, wiping a surface with something, and forviŝi is that act with for, away, welded on the front, giving wipe away, erase, and by extension delete.

Wipe what, and off what. Viŝi is transitive and the object is the thing you are cleaning, not the dirt: viŝi la tablon, wipe the table. What comes off it takes de: viŝi la polvon de la libro. Both objects can appear in the same sentence and the language does not mind which way round you build it, but the surface is the default and the pattern to copy.

The family, and where the useful distinctions are. Viŝilo is a wiper or a cloth, built with the tool suffix, and glacoviŝilo is a windscreen wiper. Viŝtuko is a tea towel or a wiping cloth. Forviŝi erases, elviŝi wipes out or rubs out, purigi cleans in general and is the wider word. Where English says wipe for both the cloth on the table and the file on the disk, Esperanto has viŝi for the first and prefers forviŝi or forigi for the second, which is a distinction worth keeping.