Today's word is NOMEN, which is a third-declension noun (gen. nominis), neuter in gender.
Latin meaning and usage: The basic meaning of this word is "name," but in grammar terminology it also means "noun." In Roman personal names, the nomen is the middle of the three names, preceded by the praenomen, and followed by the cognomen; you can read about Roman names in this Wikipedia article. There is a wide range of Latin idioms using the word nomen, and the Lewis & Short dictionary entry is well worth taking a look at.
Latin word formation: This Latin word is from the root gno- as in the verb gnosco/nosco (and cognosco); this is the same root you see at work in the English word "know."
English cognates and derivatives: Our English word "noun" comes from Latin nomen, via the French nom. Consider also "nominate" (and "nomination"), which means to put someone's name on a list of candidates. We have the word "nomenclature," from the Latin nomenclator, a servant who would call out the names of visitors, reminding his master of just who was who. A "binomial" expression in algebra is an expression with two terms. Something that is "nominally" this or that is so in name only.
Here are some examples of today's word in Latin sayings and proverbs; for more information, see the page at the Scala Sapientiae, which also contains notes on some of the proverbs cited below, as well as additional proverbs:
Sunt quidam non re, sed nomine homines.
Vive tibi et longe nomina magna fuge.
Melius est nomen bonum quam divitiae multae.
Bonum para nomen, et dormi secure.
Mutato nomine, de te fabula narratur.
Saepe sub nomine pacis bellum latet.
Bonum nomen numquam exstinguitur.
Intrat amicitiae nomine tectus amor.
O nomen dulce libertatis!
Bonae vitae numerus dierum; bonum autem nomen permanebit in aevo.
Ante lucrum nomen.
Omne capax movet urna nomen.
Amicum an nomen habeas, aperit calamitas.
Bonum parato nomen, et securus cuba.
Medici carnifices sub honesto nomine.
Vulgare amici nomen, sed rara est fides.
Pacis nomine bellum involutum reformido.
Qui semel est furans, furis nomen sibi durans.
Stat lapis et nomen tantum, vestigia nulla.