Strong's G2651 — καταμόνας (adverb)
katamonas (kat-am-on'-as) adv.
1. according to sole places
2. (adverbially) separately
[from G2596 and accusative case plural feminine of G3441 (with G5561 implied)]
KJV: alone 
Root(s): G2596, G3441 
See also: G5561 
Hebrew root: μόνος