attend (give self) continually (upon), continue (in, instant in, with), wait on (continually)

Strong’s Dictionary of Greek Words:

Greek:
προσκαρτερέω
Transliteration:
proskartereo
Phonic:
pros-kar-ter-eh’-o
Meaning:
from 4314 and 2594; to be earnest towards, i.e. (to a thing) to persevere, be constantly diligent, or (in a place) to attend assiduously all the exercises, or (to a person) to adhere closely to (as a servitor)
KJV Usage:
attend (give self) continually (upon), continue (in, instant in, with), wait on (continually)