IPA: /ðəmˈsɛlvz/
KK: /ðɛmˈsɛlvz/
A pronoun used to refer back to the subject of the sentence, often for emphasis or to indicate that the subject is also the object.
The students prepared themselves for the exam by studying all night.
The word 'themselves' is formed from 'them' (from Old Norse 'þeir', meaning they) and the reflexive suffix '-self' (meaning of oneself). The word 'themselves' refers to the individuals in question acting on their own behalf or in their own capacity.
Think of 'them' as referring to a group of people, and '-self' indicating that they are acting for their own sake. This helps you remember that 'themselves' means those people acting on their own.