The word "rattle" has multiple meanings, depending on its context.
1) In a general sense, it refers to making a loud, sharp noise by shaking or vibrating something, often with small objects inside that create the sound when moved around. For example, you might say "the baby's rattles are in the corner" meaning the baby's toy is there.
2) In another context, it can refer to a state of confusion or disarray. You could say something like "my plans were thrown into a rattle by unexpected events." This usage implies that things have become chaotic and unsettled.
3) Finally, the word can also be used figuratively to describe someone who is nervous or anxious, as if they are shaking with fear. For example, you might say "he was so scared his rattle went" meaning he was very frightened.