1.  foliage(n = noun.plant) leaf, leafage - the main organ of photosynthesis and transpiration in higher plants;
is a kind of plant organ
has parts: venation, lobe, leaf form, leaf shape
has particulars: cataphyll, floral leaf, dandelion green, pitcher, sporophyl, sporophyll, blade, leaf blade, amplexicaul leaf, greenery, verdure, leaflet, frond, pad, scale, scale leaf, fig leaf, simple leaf, compound leaf, entire leaf, crenate leaf, serrate leaf, dentate leaf, emarginate leaf, erose leaf, runcinate leaf, lobed leaf, parallel-veined leaf, parted leaf, prickly-edged leaf, rosette
Derived form verb foliate₅

2.  foliage(n = noun.artifact) foliation - (architecture) leaf-like architectural ornament;
is a kind of architectural ornament
Derived form verb foliate₂

1.  Leaves, collectively, as produced or arranged by nature; leafage; as, a tree or forest of beautiful foliage. [1913 Webster]

2.  A cluster of leaves, flowers, and branches; especially, the representation of leaves, flowers, and branches, in architecture, intended to ornament and enrich capitals, friezes, pediments, etc. [1913 Webster]

   To adorn with foliage or the imitation of foliage; to form into the representation of leaves. Drummond. [1913 Webster]

foliage, n.
1 leaves, leafage.
2 a design in art resembling leaves.

Idiom:
foliage leaf a leaf excluding petals and other modified leaves.

Etymology:
ME f. F feuillage f. feuille leaf f. OF foille: see FOIL(2)

N  vegetable, vegetable kingdom, flora, verdure, plant, tree, shrub, bush, creeper, herb, herbage, grass, annual, perennial, biennial, triennial, exotic, timber, forest, wood, woodlands, timberland, hurst, frith, holt, weald, park, chase, greenwood, brake, grove, copse, coppice, bocage, tope, clump of trees, thicket, spinet, spinney, underwood, brushwood, scrub, boscage, bosk, ceja, chaparal, motte, arboretum, bush, jungle, prairie, heath, heather, fern, bracken, furze, gorse, whin, grass, turf, pasture, pasturage, turbary, sedge, rush, weed, fungus, mushroom, toadstool, lichen, moss, conferva, mold, growth, alfalfa, alfilaria, banyan, blow, blowth, floret, petiole, pin grass, timothy, yam, yew, zinnia, foliage, branch, bough, ramage, stem, tigella, spray, leaf, flower, blossom, bine, flowering plant, timber tree, fruit tree, pulse, legume, vegetable, vegetal, vegetive, vegitous, herbaceous, herbal, botanic, sylvan, silvan, arborary, arboreous, arborescent, arborical, woody, grassy, verdant, verdurous, floral, mossy, lignous, ligneous, wooden, leguminous, vosky, cespitose, turf-like, turfy, endogenous, exogenous, green-robed senators of mighty woods, this is the forest primeval.