semipalmate

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Having partial or reduced webbing between the toes, as some wading birds do.

Century Dictionary and Cyclopedia

1. Half-webbed, as the toes of a bird; having partly webbed or imperfectly palmate feet, as a bird: applied to many species whose toes are webbed at the base only, or not more than half-way to their ends. Compare cuts under bicolligate and palmate.

Wiktionary

1. adj. semipalmated

GNU Webster's 1913

1. adj. (Zoöl.) Having the anterior toes joined only part way down with a web; half-webbed. See Illust. k under aves.