Swarm up can be replaced with several words and phrases depending on the context. A few synonyms for swarm up include gathering, clustering, assembling, or congregating. All these words imply the action of coming together in large numbers.
In sports, warming up is essential before engaging in physical activities. In this scenario, swarm up can also be substituted with phrases like preparing, loosening up, or limbering up.
In the context of technology, swarm refers to a group of devices that work together to achieve a common goal. Here, swarm up can be replaced with words or phrases like synchronize, coordinate, or align.
Overall, it's essential to use the right words or phrases that fit the context when replacing swarm up with synonyms.