Excubation
Pronunciation : Ex`cu*ba"tion n.
Etymology : [L. excubatio, fr. excubare to lie out on guard; ex out on guard; ex out + cubare to lie down.]
Definition : Defn: A keeping watch. [Obs.] Bailey.
Source : Webster's Unabridged Dictionary, 1913
Merriam-Webster's Everyday Language Reference Set: Includes: The Merriam-Webster Dictionary, The Merriam-Webster Thesaurus, and The Merriam-Webster Vocabulary Builder