[ sɛp'tɪljən ]
■ cardinal number ( plural ~s or (with numeral) same) a thousand raised to the eighth power (10 24 ).
↘ dated, chiefly Brit. a million raised to the seventh power (10 42 ).
Origin
C17: from Fr., from million , by substitution of the prefix septi- 'seven' (from L. septimus 'seventh') for the initial letters.