The plural form of dactyl, referring to multiple metrical feet or multiple fingers and toes.
From Latin and Greek pluralization of daktylos. The Latin plural -i became standard when these Greek anatomical and poetic terms entered medical and literary English.
When scanning a poem with multiple three-beat rhythms, you count your dactyli just like you'd count your fingers—it's literally the plural of finger in the context of meter!
Complete word intelligence in one call. Free tier — 50 lookups/day.