Not any thing; no thing.
An absence of anything, including empty space, brightness, darkness, matter, or a vacuum.
Something trifling, or of no consequence or importance.
A trivial remark especially in the term sweet nothings.
A nobody (insignificant person).
Well grounded or justifiable, pertinent.
Of an argument: whose conclusion is always true whenever its premises are true.
Genuine - as distinguished from efficient or regular - sacrament.
Related to the current topic, or presented within context, relevant.
Of a formula or system: such that it evaluates to true regardless of the input values.
Acceptable, proper or correct; in accordance with the rules.