parenchyma

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Anatomy The tissue characteristic of an organ, as distinguished from associated connective or supporting tissues.
2. n. Botany The primary tissue of higher plants, composed of thin-walled cells and forming the greater part of leaves, roots, the pulp of fruit, and the pith of stems.

Century Dictionary and Cyclopedia

1. n. In anatomy and zoology: The proper tissue or substance of any part or organ, as distinguished from the connective or other sustentacular tissue which it contains.
2. n. The undifferentiated body-substance or chyme-mass of the unicellular animal, as an infusorian; indistinguishable cell-substance; endoplasm.
3. n. The general substance of the interior of the parenchymatous worms.
4. n. In botany, the fundamental cellular tissue of plants: contradistinguished from prosenchyma, or fibrovascular tissue. It is the soft thin-walled tissue, with approximately isodiametric cells, which composes the soft pulp of leaves between the network of veins, the pulp of fruits, etc. In a dicotyledonous stem it forms the outer bark, the pith, and the medullary rays; in monocotyledons it is the common mass, of loose texture, through which the definite fibrovascullar bundles are distributed. While the ordinary or typical shape of the cells is polyhedral or spheroidal, there are numerous modifications, all of which formerly received special designations, but only a few principal types are now distinguished by names. Spongy parenchyma is tissue in which the cells are loosely aggregated and have large intercellular spaces. Elongated parenchyma-cells are more compactly combined than short ones, and in the upper side of leaves have received the significant name of palisade-cells. Flattened parenchyma-cells are seen in the medullary rays of dicotyledons. Collenchyma, sclerotic and suberous parenchyma, trichomes, etc., are further modifications. See collenchyma. palisadecell, sclerotic, suberous, trichome, and cuts under cellular, cystolith, and tissue.
5. n. Also parenchyme.

Wiktionary

1. n. The functional part of an organ, as opposed to supporting tissue.
2. n. botany The ground tissue making up most of the non-woody parts of a plant.

GNU Webster's 1913

1. n. (Biol.) The soft cellular substance of the tissues of plants and animals, like the pulp of leaves, the soft tissue of glands, and the like.

WordNet 3.0

1. n. the primary tissue of higher plants composed of thin-walled cells that remain capable of cell division even when mature; constitutes the greater part of leaves, roots, the pulp of fruits, and the pith of stems
2. n. animal tissue that constitutes the essential part of an organ as contrasted with e.g. connective tissue and blood vessels