Entry 1 sense Webster, 1913 Hyposkeletal · Hy·po·skel·e·tal · IPA 01 a. Beneath the endoskeleton; hypaxial; as, the hyposkeletal muscles; -- opposed to episkeletal. 1. Beneath the endoskeleton; hypaxial; as, the hyposkeletal muscles; -- opposed to episkeletal.(Anat.)