Lexical Definition

‎σπεκουλάτωρ‎ spekoulátōr (spek-oo-lat'-ore) executioner ^G:N-M
of Latin origin

executioner.

• a speculator, i.e. military scout (spy or (by extension) life-guardsman)

Abbott-Smith

*† σπεκουλάτωρ, -ορος (Rec. -ωρος), ὁ (Lat. speculator),
1. prop., a spy or scout.
2. An executioner: Mk 6:27 (v. Swete, in l.).†

Abbott-Smith References

Liddell-Scott-Jones

σπεκουλάτωρ, ορος, ὁ,

= Latin speculator, properly scout: but in the Roman Imperial army,

__1 one of the principales or head-quarters' staff of a legionary commander or provincial governor (whose duties included the carrying out of executions), [NT+4th c.AD+]
__2 one of the Imperial body-guard (speculatores Augusti),= δορυφόρος, [Refs]

_{LSJ Scripture Refs: Mark.6.27}