Answer:conditioned stimulus
Explanation:The conditioned stimulus in classical conditioning refers to the previously neutral stimulus which over time produces the same effect as the uncontioned stimulus as the person begins to associate it with the uncontioned stimulus
For example, tickling is an uncoditioned stimulus ,squirming and giggling in response to tickling is an unconditioned response, clicking of a tongue is a conditioned stimulus which yields the same response as the uncontioned stimulus.
Clicking of a tongue is a previously neutral stimulus which is over time associated with the unconditioned stimulus and because of this it bring the same feeling and a response that is now learned, the conditioned response