painter (second word) 
n.
5LME paynter < OFr pentour, ult. < L pendere, to hang: see PEND6 a rope attached to the bow of a boat for tying it as to a dock or for towing it
 >paint[er3 7pant4!r8 
pisiform  - resembling a pea in size or shape.  The smallest  bone in the writst is so named. If I remember corectly, it is the type of bone called “sesamoid”. I learned  the word sesame from Arabian Nights story
of Aladdin, and the magic words: “Open, Sesame!” The sesamoid bones form in tendons that pass across joints. The kneecap is the largest one. I didn’t know that babies have no kneecap, until just yesterday.
The kneecap appears towards end of second year.
pitta  -  a  Near East thin bread cake of which top and bottom readily separate, so that opening it on one quarter of the perimeter makes a pocket into which chopped sandwich fillings can be placed, and will not fall out when it is eaten. Very handy for lunches to take to work or to a picnic. Which reminds me of the little girl seeing a boy uriate at a picnic, exclaiming: “What a handy thing to bring to a picnic.”
pith 
n.
5ME pithe < OE pitha, akin to MDu pitte, pit of a fruit, kernel, pith of a tree6 
1	the soft, spongy tissue in the center of certain plant stems 
2	the soft core of various other things, as of a bone or feather 
3	the spongy, fibrous tissue lining the rind and surrounding the sections of an orange, grapefruit, etc. 
4	the essential part; substance; gist 
5	importance: now usually in of great pith and moment 
6	[Archaic] strength; vigor; force 
vt.
1	to remove the pith from (a plant stem) 
2	to pierce or sever the spinal cord of (an animal) in order to kill it or make it insensible for experimental purposes
And in Africa, a light weight headgear designed to be light weight, well ventilated, with brim that protected agaist excessive  exposure to the sun was called a pith helmet. (no lisping allowed) Hindi name was topee. "Only mad dogs and Englishmen go out in the noonday sun."
pithy 
adj.
pith$i[er, pith$i[est 
1	of, like, or full of pith 
2	terse and full of substance or meaning 
—SYN CONCISE 
pith$i[ly 
adv.
pith$i[ness 
n.
Considering how soft, weak, and virtually useless pith, is the definition of “pithy” is a bit surprising. I suppose it is a figure of speech based on the central position in the cross section of a branch or young tree, comparable position of the heart in anatomy, that is, central.