from The American Heritage® Dictionary of the English Language, 4th Edition
- adv. By oneself; alone. Used as a stage direction to a male character.
from the GNU version of the Collaborative International Dictionary of English
- Alone; -- chiefly used in stage directions, and the like.
from The Century Dictionary and Cyclopedia
- Alone: used chiefly in dramatic directions: as, enter the king solus. The feminine form is sola.
Latin sōlus, alone; see solo.(American Heritage® Dictionary of the English Language, Fourth Edition)