Today's word is MOS, which is also commonly found in the plural, mores. The Latin word covers an enormous range of English words, including "manner" or "custom," as well as the "habits" or "character" of an individual person. For details about the meanings of this word, see the Lewis & Short dictionary entry. This Latin word is at the root of English words like "moral" and "morality" and also "morose." Via French, we also get the form "morale."
Here are some examples of today's word in Latin sayings and proverbs; for more information, see the page at the Scala Sapientiae, which contains notes on some of the proverbs cited below, as well as additional proverbs:
Mala vita, mali mores.
O tempora, O mores!
Suus cuique mos.
Alia tempora, alii mores.
Alii homines, alii mores.
Suus est mos cuique genti.
Ex malis moribus fiunt bonae leges.
Quid leges sine moribus?
Cum fueris Romae, Romano vivito more.
Mos regit legem.
Tempore mutato, mores mutantur.
Honores mutant mores.
Sui cuique mores fingunt fortunam.
Leges moribus serviunt.
Vultus indicat mores.
Moribus antiquis res stat Romana virisque.
Antiqui mores serventur.
Ex malis moribus bonae leges natae sunt.
Terrae, ad quam pergis, cape mores, quos ibi cernis.
Oratio mores animi sequitur.