(Hebrew דעת means knowledge) The hidden sphere in the Tree of Life. Daath is the Tree of Knowledge, which is related to sexuality.
“My son, hearken to my wisdom [חכמה Chokmah]; incline your ear to my understanding [בונה Binah], to watch [your] thoughts, and your lips shall guard knowledge [דעת Daath]. – Proverbs 5
"My people are destroyed for lack of knowledge (Daath-Gnosis): because thou hast rejected knowledge (Daath-Gnosis), I will also reject thee, that thou shall be no priest to me: seeing thou hast forgotten the law of thy God, I will also forget thy children.” – Hosea 4:6