n. pl. ple·nums or ple·na (plēnə, plĕnə) 1. An assembly or meeting with all members present. 2. A condition, space, or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere. 3. The condition of being full; fullness. 4. A space completely filled with matter. 5. A space lying above the ceiling in a building but below the next floor, especially one allowing movement of air between parts of the building. [Latin plēnum (spatium), full (space), neuter of plēnus; see pelə-1 in the Appendix of Indo-European roots.] |
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