Today's word is DOMUS, which is a feminine fourth-declension noun, genitive: domus. In archaic Latin, you can sometimes find this regarded as a second-declension noun, with a genitive domi.
Latin meaning and usage: The basic meaning of domus corresponds to the English words "house" and "home." You will find adverbial forms of this noun, too: domi, "at home" and domum, "homewards, to home."
Latin word formation: Consider the adjective domesticus, the noun domicilium, as well as this nice little diminutive: domuncula.
English cognates and derivatives: We use the words "domestic" and "domicile" in English, and there is also the wonderful phrase "major-domo," from Latin maior-domūs.
Here are some examples of today's word in Latin sayings and proverbs; for more examples, see the page at the Scala Sapientiae, which also contains notes on some of the proverbs cited below:
Omnis est rex in domo sua.
Romani, ite domum!
Stet fortuna domus!
Parva domus, parva cura.
Domi manere convenit felicibus.
Domus propria, domus optima.
Domus amica, domus optima.
Propria domus omnium optima.
Domi manere tutum.
Domus divisa contra se non stabit.
Quaere vicinum ante domum, et socium ante viam.
Domi suae quilibet rex.
Luctu vacat bos cum senex moritur domi.
Una domus non alit duos canes.
Canis domi ferocissimus.
Parva domus, magna quies.
Qui altam facit domum, quaerit suam ruinam.
Beatus is qui in prosperis manet domi.