Possible Clues:

• Virginia has vain reform for Hindu sectarian
• 'Shall I compare thee to a summer's day?' has five of these
• da-DUM, da-DUM, da-DUM
• Keats feet
• Rhythmic feet
• Feet in some meters
• Keatsian feet
• Trio in 'To be, or not to be'
• Metrical feet in poetry (one of three possible spellings)
• *Feet in a sonnet