Baretti: A dictionary of the English and Italian languages
Sfogáre, v. n. & r.
1. to exhale, evaporate, cast out, send forth; 2. to overflow. Per la troppa pioggia l'acqua sfogò per tutta la campagna,the excessive rain overflowed the country; 3. to vent, allay, mitigate, ease, assuage. — la colera, to vent one's anger. — il dolore, to mitigate one's grief; 4. (med. t.) to suppurate well. Chi vuole che una piaga sfoghi bene, paghi bene il medico, he that would be well cured of a wound must pay the physician well. Sfogar la vela, (naut. t.) to let the sail go.
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
sfogare: to vent, to wreake or burst foorth as fire doth being closely raked vp.