ὑπό-στασις, -εως, ἡ
(< ὑφίστημι, to set under, stand under, support) [in LXX for מַצָּב (I Ki 13:2314:4 B), תִּקְוָה (Ru 1:12, Ez 19:5), etc., also in Wi 16:21;]
1. a support, base or foundation (in various senses).
2. substance (Arist., al.; opp. to φαντασία, ἔμφασις): He 1:3
3. steadiness, firmness (Polyb., al.), hence, assurance, confidence: II Co 9:411:17, He 3:1411:1 (here perhaps title-deed,as that which gives reality or guarantee; v. MM, xxv).†