Pressure meas (3)
I believe the answer is:
psi
(Other definitions for psi that I've seen before include "foreign letter" , "Greek letter; pressure unit" , "letter from abroad" , "one employed by Socrates?" , "Greek character" .)
I believe the answer is:
psi
(Other definitions for psi that I've seen before include "foreign letter" , "Greek letter; pressure unit" , "letter from abroad" , "one employed by Socrates?" , "Greek character" .)