Are Trial and Error?

a way of achieving an aim or solving a problem by trying a number of different methods and learning from the mistakes that you make: There's no instant way of finding a cure - it's just a process of trial and error.

Is trial and error singular or plural?

trial and error (usually uncountable, plural trials and errors) The process of finding a solution to a problem by trying many possible solutions and learning from mistakes until success is attained.

Is it trial and error or trials and errors?

In more general, commonly used, contexts, the plural form will also be trial and error. However, in more specific contexts, the plural form can also be trials and errors e.g. in reference to various types of trials and errors or a collection of trials and errors.