LXX

Multiple Entries:
  LXX    seventy  

Concise Oxford English Dictionary © 2008 Oxford University Press:
LXX

▶symbol Septuagint.

– origin special use of the Roman numeral for 70.

Concise Oxford English Dictionary © 2008 Oxford University Press:
seventy/ˈsevnti/

▶cardinal number (pl. seventies) the number equivalent to the product of seven and ten; ten less than eighty; 70. (Roman numeral: lxx or LXX)

– derivatives
seventieth ordinal number,
seventyfold adjective & adverb.

– origin OE hundseofontig, from hund- (of uncertain origin) + seofon ‘seven’ + -tig (see -ty2).