- Jaat
- Nepali for a caste or sub-caste group — the word behind "chaar jaat chhattis jaat," the traditional idiom in the Society page's title.
- Varna
- The four-tier classical Hindu caste model — Brahmin, Kshatriya, Vaishya, Shudra — as historically mapped onto hill Hindu Nepali society.
- Khas
- An Indo-Aryan hill people native to Nepal’s far west, whose language became modern Nepali. Not originally organized by Hindu caste.
- Khas Arya
- The modern constitutional category grouping Bahun, Chhetri, Thakuri and Sanyasi (Dashnami) citizens — a legal echo of the older Khas ethnonym.
- Bahun
- Hill Brahmin caste — the priestly/scholarly tier in the varna model, and part of the Khas Arya category.
- Chhetri
- Hill Kshatriya caste — the ruling/warrior tier, and Nepal’s single largest caste group (16.45% of the 2021 census).
- Thakuri
- A Chhetri sub-group; the stratum from which Nepal’s ruling Shah and Rana dynasties drew their own identity.
- Muluki Ain
- Nepal’s first written national legal code, promulgated in 1854 by Jung Bahadur Rana, which formalized a nationwide caste hierarchy.
- Tagadhari
- "Wearers of the sacred thread" — the Muluki Ain’s highest tier: hill and Newar Brahmins, Thakuri, Chhetri, and Tarai Brahmins.
- Matwali
- "Alcohol-drinkers" — the Muluki Ain’s term for groups outside the Hindu ritual hierarchy, split into a protected ("Namasinya") and an enslavable ("Masinya") tier.
- Birta
- Tax-exempt land grants historically awarded, disproportionately, to Bahun, Chhetri and Thakuri courtiers and officials.
- Janajati
- "Indigenous nationalities" — ethnic communities outside the Hindu caste hierarchy, roughly a third of the population, organized since 1990 under NEFIN.
- Adivasi
- "Indigenous" — commonly paired with Janajati (as "Adivasi Janajati") in Nepal’s constitution and inclusion policy.
- Madhesi
- Communities of the Tarai plains, home to roughly half of Nepal’s population but long under-represented in a state centered on the hill capital.
- Dalit
- Communities historically placed in the Muluki Ain’s lowest, "untouchable" tier — today a legally protected category under anti-discrimination law.
- NEFIN
- Nepal Federation of Indigenous Nationalities — the umbrella organization for the Janajati movement, founded 1991 (as NEFEN), renamed 2003.