Is it ensure, insure, or assure?
"instrument that keeps something stationary," before 1970, shortened form of Latin statim (adv.), originally "to a standstill," from status (see state (n.1)).
combining form used in forming the names of devices for stabilizing or regulating (thermostat, etc.), from Greek statos "standing, stationary," from histanai "to cause to stand," from PIE root *sta- "to stand" (see stet). First used in heliostat "an instrument for causing the sun to appear stationary" (1742).
With no delay. adj.
Something that stabilizes: barostat.
Something that inhibits: hemostat.