Brutus has calmed himself after a turbulent time and he is fully awake when the ghost manifests. The dying flame of his lamp announces the ghost's presence.
A soldier is one who fights as part of a land-based army. A soldier can be an enlisted person, a non-commissioned officer, or an officer in the army.
Definition from Wiktionary, the free dictionary. Military slang is a set of colloquial terms which are unique to or which originated with military personnel. They are often abbreviations or derivatives of the NATO Phonetic Alphabet, or otherwise incorporating aspects of formal military concepts and terms.