Original Word: ἐπιστηρίζω
Part of Speech: Verb
Transliteration: epistérizó
Phonetic Spelling: (ep-ee-stay-rid'-zo)
Short Definition: I prop up, uphold, confirm
Definition: I prop up, uphold, support, confirm, make stronger.

1991 epistērízō (from 1909 /epí, "suitably on, fitting" and 4741 /stērízō, "make firm") – properly, "prop up, uphold, support, confirm" (Souter), i.e. support (establish) in an apt, fitting way; to confirm as it builds on the Lord's previous work of faith (note the force of the prefix epi, "upon"). This process strengthens by extending the understanding that precedes, as it supports what must follow.

Word Origin
from epi and stérizó
Definition
to make stronger
NASB Translation
strengthened (1), strengthening (2).