The word "jelling" refers to the process of solidifying or strengthening something, such as a relationship or concept. There are various synonyms that can be used to describe this process, such as "solidifying," "consolidating," "strengthening," "firming up," "cementing," and "establishing." These words can be used interchangeably with "jelling" to give further emphasis to the idea of making something more certain or concrete. Whether you are describing a business partnership, a friendship, or a plan for the future, using words like these can help convey your intention to create something strong and lasting.