You can leave the search field blank: the search engine will return all entries belonging to the specified category and type.
You can use regular expressions in the search field. With regular expression search, cloud will match cloud, clouds, uncloud, and unclouding. To limit the match to entire words, delimit it with \b. For example, \bcloud\b will match only cloud, not clouds or uncloud. Omitting one of the \b's allows you to search for initial or final strings. For example, \bcloud matches cloud, clouds, and clouding, but not uncloud; whereas cloud\b matches cloud and uncloud but not clouding.
(*) Pseudo-entries are entries that are entries that are either just specific forms of other entries, such as the genitive form of another entry, or proper names that aren't an essential part of the language.