The word 'withins' can have synonyms such as within, inside, internally, inthral, and inherently. 'Within' is a common synonym of 'withins' which means inside or within the limit of a certain condition. On the other hand, 'inside' is a synonym that means close to the center or the interior. 'Internally' is a synonym that refers to the inner workings of something. 'Inthral' means to enslave or captivate. Lastly, 'inherently' means that something is an essential part or inherent quality. Using synonyms like these can help to add variety and depth to one's writing.