Unto

• POS: Preposition
• HYPHEN: un=to

CIDE DICTIONARY

Unto, prep. [OE. unto; un- (only in unto, until) unto, as far as + to to; this un- is akin to AS. until, OFries. und OS. und until, conj. (cf. OS. unt unto, OHG. unzi), Goth. und unto, until. See To, and cf. Until.].

•  To; -- now used only in antiquated, formal, or scriptural style. See To.  [1913 Webster]
•  Until; till.  Num. xxxv. 25.  [1913 Webster]

Unto, conj. 

 Until; till.  Chaucer.  [1913 Webster]

OXFORD DICTIONARY

Unto, prep. archaic = TO prep. (in all uses except as the sign of the infinitive); (do unto others; faithful unto death; take unto oneself).

Etymology

ME f. UNTIL, with TO replacing northern TILL(1)