http://www.merriam-webster.com/dictionary/significant
Main Entry: sig·nif·i·cant
Pronunciation: \-kənt\
Function: adjective
Etymology: Latin significant-, significans, present participle of significare to signify
Date: 1579
1 : having meaning; especially : suggestive <a significant glance>
2 a : having or likely to have influence or effect : important <a significant piece of legislation>; also : of a noticeably or measurably large amount <a significant number of layoffs> <producing significant profits> b : probably caused by something other than mere chance <statistically significant correlation between vitamin deficiency and disease>