Strong's G1401 — δοῦλος (noun)
doulos (dou`-los) n.
1. (involuntarily) a slave
2. (of necessity) a bond-servant
3. (figuratively) a voluntary, fully devoted servant
{literal or figurative, involuntary or voluntary; frequently, therefore in a qualified sense of subjection or subserviency}
[from G1210]
KJV: bond(-man), servant 
Root(s): G1210 
Hebrew root: δέω
Occurrences: 126