Word Summary
epistamai: to know, to understand
Original Word: ἐπίσταμαι
Transliteration: epistamai
Phonetic Spelling: (ep-is'-tam-ahee)
Part of Speech: Verb
Short Definition: to know, to understand
Meaning: to know, to understand
Strong's Concordance
know, understand.

Apparently a middle voice of ephistemi (with nous implied); to put the mind upon, i.e. Comprehend, or be acquainted with -- know, understand.

see GREEK ephistemi

see GREEK nous

Thayer's Greek Lexicon
STRONGS NT 1987: ἐπίσταμαι

ἐπίσταμαι (seems to be the Ionic form of the middle of ἐφίστημι. Isocrates, Aristotle, others, also use ἐπιστῆσαι τήν διάνοιαν, τόν νοῦν, ἑαυτόν for to put one's attention on, fix one's thoughts on; indeed, the simple ἐπιστῆσαι is used in the same sense, by an ellipsis analogous to that of τόν νοῦν with the verbs προσέχειν, ἐπέχειν, and of τήν ὄψιν with προσβάλλειν; see Lobeck ad Phryn., p. 281f Hence, ἐπίσταμαι is properly, to turn oneself or one's mind to, put one's thought upon a thing); from Homer down; the Sept. chiefly for יָדַע ; (cf. German sichworaufverstehen);

a. to be acquainted with: τί, Acts 18:25; James 4:14; Jude 1:10; τινα, Acts 19:15; with reference to what is said or is to be interpreted, to understand: Mark 14:68; 1 Timothy 6:4.

b. to know: περί τίνος, Acts 26:26; followed by an accusative with a participle Acts 24:10 (Winers Grammar, 346 (324); Buttmann, 301 (258)); followed by ὅτι, Acts 15:7; Acts 19:25; Acts 22:19; followed by ὡς, Acts 10:28; by πῶς, Acts 20:18; by ποῦ, Hebrews 11:8. (Synonym: see γινώσκω.)

STRONGS NT 1987a: ἐπίστασιςἐπίστασις, ἐπιστασεως, (ἐφίστημι, ἐφισταμαι), an advancing, approach; incursion, onset, press: τῆς κακίας (Vulg.malorumincursio), 2 Macc. 6:3, where cf. Grimm; used of the pressure of a multitude asking help, counsel, etc., τίνι (on which dative cf. Winers Grammar, § 31, 3; (Buttmann, 180 (156)); Kühner, § 424, 1) to one, 2 Corinthians 11:28 L T Tr WH (but others would have us translate it here by oversight, attention, care, a common meaning of the word in Polybius); used of a tumultuous gathering in Acts 24:12 L T Tr WH. Cf. Buttmann, as above