Lexical Definition

‎κοίμησις‎ koímēsis (koy'-may-sis) sleep ^G:N-F
from ‎κοιμάω‎

taking of rest.

• sleeping, i.e. (by implication) repose

Abbott-Smith

** κοίμησις, -εως, ἡ, [in LXX: Si 46:19 48:13*;]
a reclining, resting: Jo 11:13.†

Abbott-Smith References

Liddell-Scott-Jones

κοίμησις-ησις, εως, ἡ,

lying down to sleep, κοιμήσεις ἐπὶ θύραις [NT+5th c.BC+]

__II the sleep of death, [LXX+3rd c.AD+]

_{LSJ Scripture Refs: John.11.13}