tetrapod n.

Proto-Indo-European root meaning "four."

It forms all or part of: cadre; cahier; carillon; carrefour; catty-cornered; diatessaron; escadrille; farthing; firkin; fortnight; forty; four; fourteen; fourth; quadrant; quadraphonic; quadratic; quadri-; quadrilateral; quadriliteral; quadrille; quadriplegia; quadrivium; quadroon; quadru-; quadruped; quadruple; quadruplicate; quarantine; quarrel (n.2) "square-headed bolt for a crossbow;" quarry (n.2) "open place where rocks are excavated;" quart; quarter; quarterback; quartermaster; quarters; quartet; quarto; quaternary; quatrain; quattrocento; quire (n.1) "set of four folded pages for a book;" squad; square; tessellated; tetra-; tetracycline; tetrad; tetragrammaton; tetrameter; tetrarch; trapezium.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit catvarah, Avestan čathwaro, Persian čatvar, Greek tessares, Latin quattuor, Oscan petora, Old Church Slavonic četyre, Lithuanian keturi, Old Irish cethir, Welsh pedwar.

Proto-Indo-European root meaning "foot."

It forms all or part of: antipodes; apodal; Arthropoda; babouche; biped; brachiopod; cap-a-pie; centipede; cephalopod; cheliped; chiropodist; expedite; expedition; foot; foosball; fetch (v.); fetter; fetlock; gastropod; hexapod; impair; impede; impediment; impeach; impeccable; isopod; millipede; octopus; Oedipus; ornithopod; pajamas; pawn (n.2) "lowly chess piece;" peccadillo; peccant; peccavi; pedal; pedestrian; pedicel; pedicle; pedicure; pedigree; pedology; pedometer; peduncle; pejoration; pejorative; peon; pessimism; petiole; pew; Piedmont; piepowder; pilot; pinniped; pioneer; platypus; podiatry; podium; polyp; pseudopod; quadruped; sesquipedalian; stapes; talipes; tetrapod; Theropoda; trapezium; trapezoid; tripod; trivet; vamp (n.1) "upper part of a shoe or boot;" velocipede.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit pad-, accusative padam "foot;" Avestan pad-; Greek pos, Attic pous, genitive podos; Latin pes, genitive pedis "foot;" Lithuanian padas "sole," pėda "footstep;" Old English fot, German Fuß, Gothic fotus "foot."