verb

estropear

spoil · ruin

Hacer que algo deje de funcionar bien, se dañe o quede en mal estado.

To damage, break, or ruin: This refers to causing physical harm to an object, causing it to stop working or lose its quality or value. For example, "La lluvia va a estropear el coche" (The rain is going to damage the car).
To spoil or ruin a plan or situation: This refers to causing a situation, a surprise, or a festive event to go wrong. For example, "No quiero estropear la sorpresa" (I don't want to spoil the surprise).
Reflexive usage (estropearse): When used as a reflexive verb, it means to break down, get damaged, or go bad. This is commonly used for food that expires or machines that stop functioning, such as "La leche se ha estropeado" (The milk has gone bad).

Grammar: It is a regular transitive verb ending in -ar. It is often used as a pronominal verb (estropearse).
Origin: The etymology is debated, but it is generally thought to be derived from the Old French estropier or the Latin extropiare, which relates to the concept of removing or disabling parts of something, or related to the term "strop" or "trough."