Webster's Revised Unabridged Dictionary · 1913

Casual

Casual , adjective

[Old English casuel, French casuel, from Latin casualis, from casus fall, accident, from cadere to fall. See Case.]

1.
Happening or coming to pass without design, and without being foreseen or expected; accidental; fortuitous; coming by chance.
Casual breaks, in the general system. — W. Irving
2.
Coming without regularity; occasional; incidental; as, casual expenses.
A constant habit, rather than a casual gesture. — Hawthorne

Casual , noun

One who receives relief for a night in a parish to which he does not belong; a vagrant.