Hot-swappable refers to the capability of replacing or adding components to a system without having to shut it down. Here are some synonyms for this term: hot-pluggable, plug-and-play, seamless replacement, on-the-fly replacement, live replacement, no-downtime replacement, changeable on-the-go, dynamic replacement, easy upgrade, and instant switch. These terms might be used in different contexts depending on the field, such as computer hardware, software, electronic devices, or industrial systems. However, they all share the common characteristic of allowing components to be swapped or added without interrupting the system's performance. Such features are essential in high-availability or critical systems where downtime can have severe consequences.