ὑπό-στασις, -εως, ἡ

(ὑφίστημι, to set under, stand under, support) [in LXX for מַצָּב (1Ki.13:23 14:4 B), תִּקְוָה (Rut.1:12, Eze.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): Heb.1:3

__3. steadiness, firmness (Polyb. al.), hence, assurance, confidence: 2Co.9:4 11:17, Heb.3:14 11:1 (here perhaps title-deed, as that which gives reality or guarantee; see MM, xxv).†

(AS)

a support, base or foundation; substance; steadiness, firmness; assurance, confidence; title-deed,