Having no condyles; lacking the rounded bony projections that normally form joints in skeletal anatomy.
From Greek 'a-' (without) plus 'kondylos' (knuckle or round prominence), describing skeletal structures missing these joint-forming knobs.
Some vertebrates have acondylous vertebrae, and fish actually evolved this way first—before nature invented the rounded joint bumps we mammals use, fish just had simple flat bones sliding past each other.
Complete word intelligence in one call. Free tier — 50 lookups/day.