Known Underrealm words:
- aafla – one sixteenth of an Underrealm “day”
- agith – blue
- anzari – darkness
- bahar – storm
- caril – one sixteenth of an aafla
- dar - great
- dulkurio – thinking
- gattan – secret
- ithin – element
- jio – hole
- kal – mighty
- kanit – war
- lier – hate
- ma – servant
- maal – dark
- sa – greatest
- tai – fang
- tarin – world
- tezlari – light
- tuuran – mountain
- urai – weaver
- vakha – racer
- yumap – piercing spear
It is known that proper Tsol'teth names were separated by apostrophes – as is common with all Tsol subraces – while the names of other creatures were hyphenated. For example: If "Caril Racer" (or alternatively, "Racer of the Caril") were to be used as a Tsol’teth name, it would be spelled "Caril'vakha." On the other hand, if a hobgoblin or other such slave were to go by this title, it would be spelled "Caril-vakha." Apostrophic notation was reserved solely for the Tsol'teth; when referring to anything else, such as places, events, or things, the hyphens of slave notation are used.
Tsol'teth names never had a prefix before them denoting degrees of power, such as "Mighty" or "Great." It can be assumed that such things were taken as granted in Underrealm society.
Some common Underrealm terms:
- Anzari-tarin – World of Darkness. This refers to the Underrealm itself.
- Dar-tezlari-kanit - Great War of Light. This refers to the War of the Deeps.
- kal-tai-vakha – Mighty Fang Racers. These were creatures constantly at war with the Tsol’teth.
- Tezlari-tarin – World of Light. This refers to the surface world of Sapience.
- Tezlari-yumap – Piercing Spear of Light. This refers to the sun.
- Tezlari-ma - Servant of Light. This refers to Seleucar.