mind that dates are approximate and that the information here may not apply to all versions of English.
The evolution of the English language is characterised by three phases. The first period dates from approximately 450 (the settlement of the Angles, Saxons and Jutes in England) to 1066 AD (the Norman Conquest). At this time the language made use of almost full inflexion, and is called Anglo-Saxon, or more exactly Old English. The second period dates from the Norman Conquest to probably c.1400 (though some books differ on when this period ends) and is called Middle English. During this time the majority of the inflections disappeared, and many Norman and French words joined the language because of the profound influence of the Anglo-Norman ruling class. The third period dates from about 1400 to today (2006), and is known as Modern English, though until recently it was called New English. During the Modern English period, thousands of words have been derived by scholars from the Classical languages.
The impact of dictionaries in the definition of obsolescent or archaic forms has caused the standardisation of spelling, hence many variant forms have been consigned to the dustbin of history.
  List of archaic English words and their modern equivalents  
 
  Original word  
  Origin  
  Meaning  
  Example  
  Comments  
 art 
 form of the verb 'to be', from Old English eart 
 present second-person singular form of the verb be. 
 ... Who may stand in thy sight when once  thou art  angry? (Psalm 76:7) 
 used in Biblical/Shakespearian/poetical language 
 astonied 
 past participle of 'astony' from Middle English astonien estoner * extonare = 'to thunder '
 to stun, amaze, or astonish; astound or bewilder 
 ... and I sat astonied unitl the evening sacrifice. (Ezra 9:4) 
 used in Biblical/Shakespearian/poetical language 
 betwixt 
 from Old English betweohs or dative betweoxum (Between) 
 between 
 ... He shall lie all night  betwixt  my breasts. (Song of Solomon 1:13) 
 used in Biblical/Shakespearian/poetical language, also used in some Southern and Appalachian dialects of the United States during the 19th and 20th centuries. /Td>
 bilbo 
 From Bilbao, Spain, the best known place of manufacture 
 an obscure and seldom used word for a short sword 
 Bilbo is the Basque word for Bilbao. (Bilbo Baggins is a fictional character.) 
 bobbish 
 from bob move up and down, dance, rebound +-ish 
 brisk, well 
 Used in 1860s 
 Bouncable 
 unknown by smelliness 
 a swaggering boaster 
				
				
				
				
			
 Used in 1860s 
 Bridewell 
 from the London prison of that name 
 a prison 
 Used in 1860s (and in common current use in Nottingham where the police station attached to the Magistrates 'Court is called The Bridewell) 
 caddish 
 from the noun cad 
 wicked 
 the noun 'cad' is dying out 
 cag-mag 
 unknown 
 decaying meat 
 Used in 1860s 
 chalk scores 
 unknown 
 a reference to accounts of debt, recorded with chalk marks 
 Used in 1860s 
 coddleshell 
 unknown 
 codicil; a modification to one's legal will 
 Used in 1860s 
 Coiner 
 unknown 
 a counterfeiter 
 Used in 1860s 
 connexion 
 From French "Connexion" 
 variant spelling of connection 
 Imagination could conceive almost anything in  connexion  with this place. (At the Mountains of Madness, by H.P. Lovecraft) 
 Used in the 19th century