To take something with a "grain of salt" or "pinch of salt" is an Englishidiom that suggests to view something, specifically claims that may be misleading or unverified, with skepticism or not to interpret something literally.[1]
The phrase cum grano salis ("with a grain of salt") is not what Pliny wrote. Pliny's actual words were addito salis grano ("after having added a grain of salt").
The Latin word sal (salis is the genitive) means both "salt" and "wit", thus the Latin phrase cum grano salis could be translated to either "with a grain of salt" or "with a grain of wit", actually to "with caution"/cautiously.[3]