Strong's G1987 — ἐπίσταμαι (verb)
epistamai (ep-is'-tam-ai) v.
1. to put the mind upon, i.e. comprehend, or be acquainted with
[apparently a middle voice of G2186 (with G3563 implied)]
KJV: know, understand 
Root(s): G2186 
See also: G3563 
Hebrew root: ἐφίστημι
Occurrences: 14