Question

what is base. definition

Answer 1

If the base you are asking for Is of chemistry then
A substance which when dissolved in water dissociates or produces hydroxide ions is known as a base.

Answer 2

bases are substances that ,in aqueous solution are slippery to touch,taste, astringent , changes the colour of indicators(e.g.,turn red litmus to blue),react with acids to form salts,promote certain chemical reactions