It is possible to search for partial words, but only if you know the start of the word. From the article https://dev.evernote.com/doc/articles/search_grammar.php:
So if I type in "creat*" as a search term, it will find "create," "created," "creates," "creating," "creator," "creative," "creature," etc. But if I type in "*reat" it won't find anything. In fact, when I start typing, it searches for words beginning with all the characters I've typed as I type them. Putting * at the beginning of the search term is the same as putting nothing; i.e., "*rea" and "rea" will both find "real," "reality," "read," etc., but will not find "create," "treat," "breathe," etc.