1.  The flower of a plant, or the essential organs of reproduction, with their appendages; florescence; bloom; the flowers of a plant, collectively; as, the blossoms and fruit of a tree; an apple tree in blossom. [1913 Webster]
" The term has been applied by some botanists, and is also applied in common usage, to the corolla. It is more commonly used than flower or bloom, when we have reference to the fruit which is to succeed. Thus we use flowers when we speak of plants cultivated for ornament, and bloom in a more general sense, as of flowers in general, or in reference to the beauty of flowers." [1913 Webster]
"Blossoms flaunting in the eye of day." [1913 Webster]

2.  A blooming period or stage of development; something lovely that gives rich promise. [1913 Webster]
"In the blossom of my youth." [1913 Webster]

3.  The color of a horse that has white hairs intermixed with sorrel and bay hairs; -- otherwise called peach color. [1913 Webster]

1.  To put forth blossoms or flowers; to bloom; to blow; to flower. [1913 Webster]
"The moving whisper of huge trees that branched
And blossomed." [1913 Webster]

2.  To flourish and prosper; to develop into a superior type. [1913 Webster]
"Israel shall blossom and bud, and full the face of the world with fruit." [1913 Webster]

3.  to appear or grow as if by blossoming; to spread out rapidly. [PJC]

blossom, n. & v.
--n.
1 a flower or a mass of flowers, esp. of a fruit-tree.
2 the stage or time of flowering (the cherry tree in blossom).
3 a promising stage (the blossom of youth).
--v.intr.
1 open into flower.
2 reach a promising stage; mature, thrive.

Derivative:
blossomy adj.

Etymology:
OE blostm(a) prob. formed as BLOOM(1)

VB  prosper, thrive, flourish, be prosperous, drive a roaring trade, do a booming business, go on well, go on smoothly, go on swimmingly, sail before the wind, swim with the tide, run smooth, run smoothly, run on all fours, rise in the world, get on in the world, work one's way, make one's way, look up, lift one's head, raise one's head, make one's fortune, feather one's nest, make one's pile, flower, blow, blossom, bloom, fructify, bear fruit, fatten, keep oneself afloat, keep one's head above water, hold one's head above water, land on one's feet, light on one's feet, light on one's legs, fall on one's legs, fall on one's feet, drop into a good thing, bear a charmed life, bask in the sunshine, have a good time of it, have a fine time of it, have a run of luck, have the good fortune, to, take a favorable turn, live on the fat of the land, live off the fat of the land, live in clover.

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.

blossom forth, blossom out, canker blossom