Is Sodium Hydroxide an acid?

1. Acid: A compound or species which gives ${\mathrm{H}}^{+}$ ion in an aqueous solution called acid. Example: $\mathrm{HCl},{\mathrm{H}}_2{\mathrm{SO}}_4$
2. The formula of sodium hydroxide is $\mathrm{NaOH}$.
3. Sodium hydroxide gives ${\mathrm{Na}}^{+}\mathrm{and}{\mathrm{OH}}^{-}$.
4. The compound which gives ${\mathrm{OH}}^{-}$ ion is called a base.

Hence, sodium hydroxide is not an acid but a base.