synonychia

syn·o·nych·i·a

(sin'ō-nik'ē-ă),
Fusion of two or more nails of the digits, as in syndactyly.
[sin- + G. onyx (onych-), nail]

syn·o·nych·i·a

(sin'ō-nik'ē-ă)
Fusion of two or more nails of the fingers or toes, as in syndactyly.
[syn- + G. onyx (onych-), nail]