The term 'center of activity' can be described by a variety of words, including 'HUB' (3 letters), 'HOTHOUSE' (8 letters), 'BEEHIVE' (7 letters), 'LOCUS' (5 letters), 'HOTBED' (6 letters), 'mecca' (5 letters), 'HIVE' (4 letters), 'NEXUS' (5 letters), 'ganglion' (8 letters), and 'focalpoint' (10 letters). Each of these words implies a place or situation that is the center of attention, energy, or activity. For example, a HUB is a central point for transportation or communication, while a HOTHOUSE is a place where plants are grown in a controlled environment. A BEEHIVE is a structure where bees live and work, and a LOCUS is a particular point or place. A HOTBED is an area of intense activity or growth, and a mecca is a place of pilgrimage or great interest. A HIVE is a structure where bees live and work, and a NEXUS is a connection or link between people or things. A ganglion is a group of nerve cells, and a focalpoint is a center of attention or activity.