pentagon English · revision 889

+ ==Pronunciation==

+ * IPA: /ˈpɛn.təˌɡɑn/, /ˈpɛn.tə.ɡən/^(Wiktionary)

+

+ ==Etymology==

+ It is [[bor|frm|pentagone]] or directly [[der|la-lat|pentagōnum]],^(AHD)^(Barnhart 1995)^(Etymonline)^(MW Collegiate)^(RHWU) [[der|grc|πεντάγωνον|tr=pentágōnon]], the neuter of ''pentágōnos'' “five-angled”,^(AHD)^(Barnhart 1995)^(Etymonline)^(MW Collegiate)^(RHWU) [[af|grc|πέντε|γωνία|tr1=pénte|tr2=gōnía|t1=five|t2=angle]].^(Barnhart 1995)^(Etymonline)^(MW Collegiate)

+

+ ==Earliest recorded meaning==

+ A plane figure with five angles and five sides (1560s–71);^(Etymonline)^(Barnhart 1995)^(MW Collegiate)^(OED 1989) as an adjective, five-angled (1570).^(OED 1989)

+

+ ==Semantic evolution==

+ In fortification a ''pentagon'' was a fort with five bastions (1571).^(OED 1989)^(Wiktionary) The headquarters of the US Department of Defense in Arlington, Virginia, completed in 1942, was named the Pentagon for its shape,^(Etymonline)^(OED 1989)^(RHWU) and from 1945 the name has been used allusively for the US military leadership.^(Etymonline)^(MW Collegiate)

+

+ ==Timeline==

+ * 1570 – the five-sided figure.^(OED 1989)^(Barnhart 1995)^(MW Collegiate)

+ * 1571 – a fort with five bastions.^(OED 1989)

+ * 1942 – the Pentagon building completed.^(Etymonline)

+ * 1945 – the US military leadership.^(Etymonline)^(MW Collegiate)^(OED 1989)

+

+ ==Modern meaning==

+ ===Noun===

+ # A [[polygon]] with five sides and five angles.^(AHD)^(MW Collegiate)^(RHWU)^(Wiktionary)

+ # ''(the Pentagon)'' The headquarters of the US Department of Defense; hence, the US military establishment.^(AHD)^(MW Collegiate)^(RHWU)

+

+ ==Word family==

+ * [[pentagonal]]

+

+ ==Related words==

+ * [[pentagram]]

+ * [[polygon]]

+ * [[hexagon]]

+ * [[octagon]]

+ * [[knee]]

+

+ ==References==

+ {{reflist}}