Having no true body cavity or coelom; describing organisms with a body plan lacking an internal space between the gut and body wall.
From Greek 'a-' (without) plus 'koilos' (hollow) plus '-ous' (full of). This biological term specifically describes body organization in simpler animals.
Flatworms are acoelomous—their bodies are essentially solid except for a simple gut tunnel, making them so flat they can squeeze through impossible spaces and regenerate from tiny fragments.
Complete word intelligence in one call. Free tier — 50 lookups/day.