The Collaborative International Dictionary of English v.0.48:

Splayfoot \Splay"foot`\, n.; pl. Splayfeet.
   A foot that is abnormally flattened and spread out; flat
   foot.
   [1913 Webster] Splayfoot

The Collaborative International Dictionary of English v.0.48:

Splayfoot \Splay"foot`\, Splayfooted \Splay"foot`ed\ a.
   Having a splayfoot or splayfeet.
   [1913 Webster]

WordNet (r) 3.0 (2006):

splayfoot
    adj 1: having feet that turn outward [syn: splayfooted,
           splayfoot] [ant: pigeon-toed]
    n 1: a foot afflicted with a fallen arch; abnormally flattened
         and spread out [syn: flatfoot, splayfoot, pes planus]

Moby Thesaurus II by Grady Ward, 1.0:

90 Moby Thesaurus words for "splayfoot":
   arch, bandy, bandy-legged, blemished, bloated, bowlegged, bowlegs,
   camelback, cleft palate, club-footed, clubfoot, crookback, defaced,
   defacement, deformation, deformed, deformity, digit, disfigured,
   disfigurement, dog, dwarfed, extremity, fetlock, flatfoot,
   flatfooted, foot, forefoot, forepaw, freakishness, grotesque,
   harefoot, harelip, heel, hoof, humpback, hunchback, ill-made,
   ill-proportioned, ill-shaped, instep, knock-knee, knock-kneed,
   kyphosis, lordosis, malconformation, malformation, malformed,
   marred, misbegotten, misproportion, misproportioned, misshape,
   misshapen, monstrosity, monstrous, mutilated, mutilation,
   out of shape, pad, pastern, patte, paw, pedal extremity, pedes,
   pes, pied, pigeon-toed, pug, pug-nosed, rachitic, rickety, simous,
   snub-nosed, sole, stumpy, swayback, swaybacked, talipedic, talipes,
   teratology, toe, tootsy, torticollis, trotter, truncated,
   truncation, ungula, valgus, wryneck