Origin and history of zygodactyl

metrical foot, late 14c., from Latin dactylus, from Greek daktylos, a unit of measure (a finger-breadth), also "a fruit of the date tree, a date," literally "finger" (also "toe"), a word of unknown origin. The metrical use (a long syllable followed by two short ones) is by analogy with the three joints of a finger. In English versification it refers to an accented syllable followed by two unaccented. The "date" sense also sometimes was used in early Modern English.

Proto-Indo-European root meaning "to join."

It might form all or part of: adjoin; adjust; conjoin; conjugal; conjugate; conjugation; conjunct; disjointed; enjoin; injunction; jugular; jostle; joust; join; joinder; joint; jointure; junction; juncture; junta; juxtapose; juxtaposition; rejoin (v.2) "to answer;" rejoinder; subjoin; subjugate; subjugation; subjunctive; syzygy; yoga; yoke; zeugma; zygoma; zygomatic; zygote.

It might also be the source of: Sanskrit yugam "yoke," yunjati "binds, harnesses," yogah "union;" Hittite yugan "yoke;" Greek zygon "yoke," zeugnyanai "to join, unite;" Latin iungere "to join," iugum "yoke;" Old Church Slavonic igo, Old Welsh iou "yoke;" Lithuanian jungas "yoke," jungti "to fasten to a yoke;" Old English geoc "yoke."