vatten.

From earlier vaten, from Middle Dutch vāten, from Old Dutch *faton, from Proto-West Germanic *fatōn, from Proto-Germanic *fatōną. By surface analysis, vat (“vat, keg, vessel”) + -en. The short vowel, which appears from the 15th century, is usually explained through influence of the underlying noun vat (plural vaten). However, one may object to this that verb and noun are usually not closely associated. An alternative theory derives it from the contracted preterite vatte (from earlier vātede), in which the vowel would have been reshortened because of the following geminate. In this case, the objection is that the same did not happen in any other verb (like haten etc.). Finally, an intensive derivation is also imaginable (cf. pairs such as schrapen ~ schrappen).