Tahāsus is when a person, while showing generosity and respectful behavior to someone of a lower rank than themselves, thereby lowers the status of the other. (Mizān, 74)
tāhir (tāhir-i bāṭin; tāhir-i sirr; tāhir-i sirr wa ʿalāniyya; tāhir-i ẓāhir)
Tāhir is the one whom Allah has protected from opposing (Him).
Tāhir-i ẓāhir is the one whom Allah has protected from maʿṣiyya (outward sin).
Tāhir-i bāṭin is the one whom Allah has protected from the whisperings of Satan and from others (besides himself).