It sometimes happens that your gams have had enough, too much ambling has jumbled your brains, your breath is pale, your face is short, and you just haven't the strength to carry on. In such cases of duress, it is customary to fold oneself at the hamstrings, create an approximate L-shape with flank and loin, and abandon one's coccyx, lumbars, and everything else that follows to the inimical pull of gravity. Occasionally (though don't count on it!), one's downward vectorizing glutes are impeded by an equal but opposite force. This impediment is referred to in the vulgate as “chair.” The semi-lapsarian discovery of “chair” is called “sitting.”
There are chairs all around us. There are thousands of chairs lurking in disguise, but don't be fooled: Of course, chaises-longues and their American variant, lawnchairs, are chairs. Settees, sofas, ottomans, and (hold on to your curds) tuffets are all chairs. Backless chairs exist, known as stools. You might come upon a type of chair public: “the parkbench,” or yet again “the churchpew.” Fauteuils & Bergères are chairs where theoreticians spend hours. Rockers, Wheelers, and some Walkers are octogenarians' chairs. Thrones are presumably chairs for kings. Lay-z-boys and fold-out beds are chairs where zzz's are caught. (All beds, in fact, are merely chairs untroubled by perpendiculars.) Hammocks are often used as chairs, as well as stairsteps, ski-lifts, street-curbs, kitchen counters, the trunk of your car, the back of your friend, an upturned box, the Dead Sea, and so on and so forth. Anything is a chair, in sum, which is roughly horizontal and halts Sir Gluteus Maximus upon his descent.
The “chair of a board,” however, is not a chair, but rather a metonymic for the man sitting in the chair at the head of the table, which head is also metonymic, referring to the organ with which the man in the chair presides – though often the presiding organ is said to be the antonym of his anterior (don't make me say it) – and besides, rarely do we ever talk about the foot of a table, and unless we are carpenters, never the foot of a chair. (Wheww! I'm in my chair after that one!)
But the chair has hams or gammons of its own, called “legs,” and a “back” often made of the same material, usually sturdy wood, hard plastic, or concrete, and sometimes fitted together by “holes” and “tongues” - or mortise and tenon, jargonistically. Some varieties of chair have what are called “ears,” and these almost invariably have “arms.” No chair (as far as I'm aware) has a “head.” The head is provided by the occupant.
For in all seriosity, a chair is the shadow of a human torso suspended in air. A simulacrum. A homunculus. Our little scaffold. It cups our weary frame in its palms. It is the copula between our subject and the ground's predicate. It grounds us. It's where we can rest, retreat, catch up on the news. Sometimes a chair is all a man or woman needs, though it often passes beneath us unnoticed. For some of us, it is all there is – who buzz from chair to chair to chair like a bumblebee pollinating flowers. Some of us can never stay too long in a chair. Some of us: a chair is all we get.
How many Rigobertos in this country haven't a home, sleep in de-curbed chairs in janitor's closets where they work, their sole possession among the mopbuckets and weedwhackers, their private refuge, the boat-where-they-are-Captain, as they're guided through their past, present, future by constellations of memory, and question their fate, come forty years too late to this godkissed Land O' Plenty?
(That's a rhetorical question)