Meet your meter: The "Restrict to meter" strip above will show you the related words that match a particular kind of metrical foot. Meter is represented as a sequence of x and / symbols, where x represents an unstressed syllable and / represents a stressed syllable. (See "Slash & x" notation for more info on how this works.) Once you select a meter, it will "stick" for your searches until you unselect it.

Vowel power! Use the "Primary vowel" option under Show filters to restrict the results to a particular primary vowel sound.