In this case Google Translate gives the translation "splash around", which I suppose could be derived from the components, but Google uses it's own database of translations. The larger question though is what strategy to use if the usual references come up dry. First, add dict.cc and DWDS (as mentioned in the comments) to your list of go to references. DWDS has both a dictionary and a usage database, which are both useful depending on the situation. (The first dictionary I go to is Wiktionary, which doesn't cover some of the more unusual words, but it's easy to read and covers most of what you might find out there in the wild.) Also try Google Translate and DeepL; we all know their AI isn't perfect but it can give you a starting point. For technical or specialized words try the German Wikipedia, the trick I often use is to find the article there, then look on the left side of the page for versions of the article in other languages and click on English. You might also try doing a regular Google search on the word. I tried this in this case and it turned up a few old dictionaries, example link. Then of course don't underestimate the power of context. If all that fails then do a search here and ask if nothing relevant comes up. With the internet there are many resources available that didn't exist in the past, so you don't have to just rely on dictionaries nowadays.