[safety valve] n (1813) 1: an automatic escape or relief valve (as for a steam boiler)
2: an outlet for pent-up energy or emotion
3: something that relieves the pressure of overcrowding
[safety valve] n (1813) 1: an automatic escape or relief valve (as for a steam boiler)
2: an outlet for pent-up energy or emotion
3: something that relieves the pressure of overcrowding
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012