Abarim Publications' online Biblical Greek Dictionary
The noun ακρον (akron) means extremity, or the highest or farthest point: tip, top, end. It comes from ακρος (acros), topmost, outermost, in turn from the nouns ακη (ake), point, and ακις (akis), any pointy object (needle, chisel, arrow, hook, even desire), which ultimately hail from the Proto-Indo-European root "hek-", sharp or pointed, from which also stems the Latin acere, sour (hence the English acid), and the Germanic ahar (hence the English ear).
Our noun is used 6 times in the New Testament, see full concordance, and from it derive:
- The noun ακροβυστια (akrobustia), which either describes the physical foreskin, or the condition or status of having a foreskin (i.e. not being circumcised), or the collective state of a whole culture of men that have an intact foreskin (i.e. the foreskinned ones; the culture based on being uncircumcised). The first part of our word comes from ακρον (akron), tip, but the origin of the second part is debated. Some suggest it's the otherwise unused verb βυω (buo), to stuff or stow away (or block, as in one's nose), but others insist it's the familiar Hebrew term בשת (boshet), shame. That would mean that our noun literally means extremity-shame, as opposed to the extremity-confidence that circumcision would imply.
As we discuss in our elaborate article on περιτομη (peritome), meaning circumcision, circumcision had nothing to do with advertising the membership of some group (or else the covenant with Abraham would have been sealed with something like a big red dot between Abraham's eyes), but rather with behavior modification. More specifically: circumcision was instated to aid humanity's transition between an existence based on the wild swings of natural reflexes (scream, rape and kill when agitated; like an animal) to one based on sophisticated restraint: equalized and predictable (not unlike the Sabbath, which was initiated to force mankind off dependency on natural cycles). When circumcision was initiated, the world at large was wholly natural, and physical circumcision was needed to force a small sub-population into behavioral sophistication. When the merits of manners were sufficiently demonstrated, and parents began to consciously raise their sons to curb their various enthusiasms, physical circumcision was no longer necessary, and having a ακροβυστια (akrobustia) should no longer necessarily signify one's barbaric or unsophisticated mind (Romans 2:25-27). This noun is used 20 times; see full concordance.
- Together with the noun γωνια (gonia), meaning corner or angle: the noun ακρογωνιαιος (akrogoniaios), meaning corner-stone, main aspect or most prominent feature (i.e. foundation). This term is not a common Greek architectural term, and does not appear to describe the keystone of the widely applied Roman arch (as is often suggested), but is rather a translation of the Hebrew term אבן ראש פנה ('eben rosh paneh), which combines the words אבן ('eben), stone, ראש (rosh), head, chief or top, and פנה (paneh), turning or facial feature (Psalm 118:22, Job 38:6, Jeremiah 51:26). Our Greek word is used in Ephesians 2:20 and 1 Peter 2:6 only.
- Together with the otherwise unused noun θις (this), meaning heap or pile (mostly of sand: a dune, sand-bank or duny beach): the noun ακροθινιον (akrothinion), meaning the top of a pile, the topmost, the best. In the classics this word occurs often in plural and often in association with offerings (particularly of war booty) to deities, and particularly certain choice items conspicuously placed atop the pile. In the New Testament this word occurs in Hebrews 7:4 only, in the formulation "a tenth of the ακροθινιον (akrothinion)", which corresponds to "a tenth of כל (kol)" in the Hebrew original of Genesis 14:20. The Hebrew original, however, did not speak of a war booty that was purloined from the vanquished, but rather a dedication of a portion of Abraham's own offspring: the Levites (the word θις, this, mostly describes piles of sand, which is what Abraham's offspring would be like — Genesis 22:17).