A period of inactivity can be described by the crossword solutions of STASIS (6 letters), DOWNTIME (8 letters), REST (4 letters), rests (5 letters), and INERTIA (7 letters). STASIS refers to a state of balance or equilibrium, while DOWNTIME is a period of inactivity or idleness. REST is a period of relaxation or sleep, and rests are pauses or interruptions in activity. INERTIA is the resistance of any physical object to a change in its state of motion or REST. All of these terms refer to a period of inactivity or lack of movement.