1. Having no ribs or no visible ribs

Antonym: ribbed

• noninheritable
• noninstitutional
• noninstitutionalised
• noninstitutionalized
• nonintegrated
• nonintellectual
• noninterchangeable
• noninterference
• nonintersecting
• nonintervention
• noninvasive
• nonionic
• nonionised
• nonionized
• nonjudgmental
• nonkosher
• nonleaded
• nonlegal
• nonlethal
• nonlexical
• nonlexically
• nonlinear
• nonlinear correlation
• nonlinear distortion
• nonlinear system