| LISSENCEPHALIES | Sorry, definition not available. |
| MEGALOCEPHALIES | • MEGALOCEPHALY n. the condition of having an unusually large head or cranial capacity, also MEGACEPHALY. |
| MYELENCEPHALONS | • MYELENCEPHALON n. the posterior part of the developing vertebrate hindbrain or the corresponding part of the adult brain composed of the medulla oblongata. |
| PALAEOECOLOGIES | • palaeoecologies n. Plural of palaeoecology. • PALAEOECOLOGY n. the study of early ecology. |
| PALATABLENESSES | • PALATABLENESS n. the state of being palatable. |
| PARALLELEPIPEDS | • parallelepipeds n. Plural of parallelepiped. • PARALLELEPIPED n. a solid figure with each face a parallelogram. |
| PHLEBOSCLEROSES | • PHLEBOSCLEROSIS n. hardening and loss of elasticity of the veins. |
| PLACELESSNESSES | Sorry, definition not available. |
| PLAUSIBLENESSES | • PLAUSIBLENESS n. the state of being plausible. |
| PLEASURABLENESS | • pleasurableness n. The characteristic of being pleasurable. • PLEASURABLE n. giving pleasure. |
| PLENTIFULNESSES | • PLENTIFULNESS n. the state of being plentiful. |
| PULSELESSNESSES | • PULSELESSNESS n. the state of being pulseless. |
| SEPTENDECILLION | • septendecillion num. (Rare, US, modern British & Australian, short scale) 1054. • septendecillion num. (Rare, dated British & Australian, long scale) 10102. • SEPTENDECILLION n. ten to the power of 54. |
| SLEEPLESSNESSES | • sleeplessnesses n. Plural of sleeplessness. • SLEEPLESSNESS n. the state of being sleepless. |
| SUPEREXCELLENCE | • superexcellence n. Supreme excellence. • SUPEREXCELLENCE n. excellence to a very high degree. |
| UNHELPFULNESSES | • unhelpfulnesses n. Plural of unhelpfulness. • UNHELPFULNESS n. the quality of being unhelpful. |