thermostat
1. ther.mo.stat \'th*r-m*-.stat\ \.th*r-m*-'stat-ik\ \-i-k(*-)le-\ n : an automatic device for regulating (as by the supply of gas or electrici ty to a heating apparatus) temperature; also : a similar device for actuating fire alarms or for controlling automatic sprinklers - ther.mo.stat.ic aj 2. thermostat vt or ther.mo.stat.ed or ther.mo.stat.ted; or ther.mo.stat.ing; or ther.mo.stat.ting : to provide with or control by a thermostat