trabecula

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A small supporting beam or bar.
• noun Anatomy Any of the supporting strands of connective tissue projecting into an organ and constituting part of the framework of that organ.
• noun Any of the fine spicules forming a network in cancellous bone.

from The Century Dictionary.

• noun In botany, one of the projections from the cell-wall which extend like a cross-beam or cross-bar nearly or quite across the cell-cavity of the ducts of certain plants, or the plate of cells across the cavity of the sporangium of a moss.
• noun plural In anatomy, the fibrous cords, layers, or processes of connective tissue which ramify in the substance of various soft organs, as the spleen, kidney, or testicle, conferring upon them greater strength, stability, or consistency.
• noun In embryology, one of a pair of longitudinal cartilaginous bars, at the base of the skull, in advance of the end of the notochord and of the parachordal cartilage, inclosing the pituitary space which afterward becomes the sella turcica; in the human embryo, one of the lateral trabecules of Rathke.
• noun One of the calcareous plates or pieces which connect the dorsal and ventral walls of the corona in echinoderms.
• noun One of the fleshy columns, or columnæ carneæ, in the ventricle of the heart, to which the chordæ tendineæ are attached: more fully called trabecula carnea.
• noun In entomology, one of the pair of movable appendages on the head, just in front of the antennæ, of some mallophagous insects, or bird-lice, as those of the genus Docophorus. They have been supposed to represent the rudiments of a second pair of antennæ. Also trabeculus.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Anat.) A small bar, rod, bundle of fibers, or septal membrane, in the framework of an organ part.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A small supporting beam.
• noun anatomy A small mineralized spicule that forms a network in spongy bone.
• noun anatomy A fibrous strand of connective tissue that supports it in place.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun rod-shaped structures of fibrous tissue that divide an organ into parts (as in the penis) or stabilize the structure of an organ (as in the spleen)