Adjective
Of or pertaining to the thigh or leg, or to any of the parts called crura; as, the crural arteries; crural arch; crural canal; crural ring.
Source: Webster's dictionaryThe leg (between the knee and the ankle) is the crus and crural area, the lateral aspect of the leg is the peroneal area, and the calf is the sura and sural region. Source: Internet
The female platypus, in common with echidnas, has rudimentary spur buds that do not develop (dropping off before the end of their first year) and lack functional crural glands. Source: Internet
The slime glands themselves are probably modified crural glands. citation All three structures correspond to an evolutionary origin in the leg pairs of the other segments. Source: Internet