ὑπόστασις

ὑπό-στασις, -εως, ἡ

(ὑφίστημι, to set under, stand under, support) [in LXX for מַצָּב (1 Kong 13,23; 14,4 B), תִּקְוָה (Rut 1,12, Ezk 19,5), etc., also in Wis 16,21 ;]

1. a support, base or foundation (in various senses).

2. substance (Arist., al.; opposite to φαντασία, ἔμφασις): Hebr 1,3

3. steadiness, firmness (Polyb., al.), hence, assurance, confidence: 2 Kor 9,4; 11,17, Hebr 3,14; 11,1 (here perhaps title-deed, as that which gives reality or guarantee; see MM, xxv).†