Etymology
Advertisement
pillar (n.)

c. 1200, piler, "a column or columnar mass, narrow in proportion to height, either weight-bearing or free-standing," from Old French piler "pillar, column, pier" (12c., Modern French pilier) and directly from Medieval Latin pilare, from Latin pila "pillar, stone barrier," a word of unknown etymology. The figurative sense of "prop or support of an institution or community" is recorded from early 14c. Related: Pillared.

In medieval architecture often made so as to give the appearance of several shafts around a central core; "by architects often distinguished from column, inasmuch as it may be of any shape in section, and is not subordinated to the rules of classic architecture" [Century Dictionary].

Phrase pillar to post "from one thing to another without apparent or definite purpose" is attested from c. 1600, late 15c. as post to pillar, mid-15c. as pillar and post; but the exact meaning is obscure. Earliest references seem to allude to tennis, but post and pillar is recorded as the name of a game of some sort c. 1450. The theory that the expression is from pillar as the raised ground at the center of a manège ring around which a horse turns is unlikely because that sense seem to date only to 18c.

The Pillars of Hercules are the two hills on opposite sides of the Straits of Gibraltar, Abyla in Africa and Calpe in Europe, said to have been torn asunder by Hercules.

Related entries & more 
Advertisement
pilaster (n.)

"a square column or pillar," 1570s, from French pilastre (1540s), from Italian pilastro, from Medieval Latin pilastrum (mid-14c.), from pila, "buttress, pile" (from Latin pila, see pillar) + Latin -aster, suffix "expressing incomplete resemblance" [Barnhart].

Related entries & more 
pillory (n.)

"frame of wood erected on a post or pole with holes into which were put the head and hands of an offender who was thus exposed for public derision and abuse," mid-14c., pillorie (attested in Anglo-Latin from late 12c., in surnames from mid-13c.), from Old French pilori "pillory" (mid-12c.), which is related to Medieval Latin pilloria, but all are of uncertain origin. Perhaps a diminutive of Latin pila "pillar, stone barrier" (see pillar), but OED finds this proposed derivation "phonologically unsuitable."

Related entries & more 
pile (n.1)

early 15c., "heap or stack of something," usually consisting of an indefinite number of separate objects arranged in a more or less regular conical or pyramidal form, from Old French pile "a heap, a stack," and directly from Latin pila "a pillar," also "stone barrier, pier" (see pillar).

The sense development in Latin would have been from "pier, harbor wall of stones," to "something heaped up." Middle English pile also could mean "pillar supporting something, pier of a bridge" (mid-15c.).  In English, the verb in the sense of "to heap (up)" is recorded from c.1400.

Middle English also had a noun pile meaning "castle, tower, stronghold (late 14c.), which persisted in a sense of "large building." OED regards this as a separate word, of doubtful origin, but other sources treat them as the same.

Related entries & more 
stylite (n.)
ascetic living on the top of a pillar, 1630s, from Ecclesiastical Greek stylites, from stylos "pillar," from PIE root *sta- "to stand, make or be firm."
Related entries & more 
Advertisement
capital (n.3)
"head of a column or pillar," late 13c., from Anglo-French capitel, Old French chapitel (Modern French chapiteau), or directly from Latin capitellum "head of a column or pillar," literally "little head," diminutive of caput "head" (from PIE root *kaput- "head").
Related entries & more 
column (n.)

mid-15c., "a pillar, long, cylindrical architectural support," also "vertical division of a page," from Old French colombe (12c., Modern French colonne "column, pillar"), from Latin columna "pillar," collateral form of columen "top, summit," from PIE root *kel- (2) "to be prominent; hill."

In the military sense "formation of troops narrow in front and extending back" from 1670s, opposed to a line, which is extended in front and thin in depth. Sense of "matter written for a newspaper" (the contents of a column of type) dates from 1785.

Related entries & more 
balustrade (n.)
"row of balusters supporting a railing," 1640s, from French balustrade (17c.), from Italian balaustrata "provided with balusters," from balaustro "small pillar" (see baluster).
Related entries & more 
columnar (adj.)

"having the form of a column; of or pertaining to a column," 1728, from Late Latin columnaris "rising in the form of a pillar," from columna "column" (see column).

Related entries & more 
Asherah (n.)
wooden pillar used as symbol of Canaanite goddess Ashera, 1839, a name of unknown origin.
Related entries & more