Definition of tridactyl in English:
 tridactyl
adjective trʌɪˈdaktɪltrīˈdaktl
Zoology (of a vertebrate limb) having three toes or fingers.
 Example sentencesExamples
-  Podokesaurid (= Coelophysid) theropods are indicated by the presence of numerous small to medium-large sized tridactyl footprints (Grallator and larger forms).
 -  The foot is functionally tridactyl, with digits II - IV bound together and largely functioning as a single unit.
 -  In the foot, the fifth toe was reduced to a single metatarsal, and the first toe was reduced and raised off the ground, leaving a functionally tridactyl foot.
 -  Ornithopod prints are nearly always tridactyl with three stout and broadly spreading toes so that the resulting footprint has the outline of a trefoil.
 
Origin
  
Early 19th century: from tri- 'three' + Greek daktulos 'finger'.