Today's word is the second declension noun, POPULUS. The basic meaning of this word is "people" in the sense of "the public, the populace." But be careful: populus has all short vowels, while there is also a word pōpulus, with a long o, which is a feminine noun, meaning "poplar," that is, the poplar tree.
There are all kinds of English words that derive from Latin populus, meaning "people," such as "population," "populist," and "popular," for example - and also "pop music." The English word "people" also comes from the Latin, via the Anglo-French people, from Old French peupel. The Spanish word pueblo also comes from Latin populus.
It is also worth noting here an unusual Latin word formed from populus: the verb populor (populari). The literal meaning of the word is for a mass of people to pour into a region. Well, since that is often something that brings havoc and destruction to the original inhabitants of that region, the Latin verb populari usually means, by metaphorical extension, "to lay waste, destroy, plunger, pillage."
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:Caveat populus.
Vox populi, vox Dei.
Ibi valet populus, ubi valent leges.
Maximus magister populus.
Quales principes, tales populi.
Populus vult decipi, ergo decipiatur.
Ita populus, sic sacerdos.
Senatus Populusque Romanus
Maximus erroris populus magister.
Salus populi suprema lex esto.
Saepe luit populus poenas unius iniqui.
Populus est novarum cupiens pavidusque.
Iustitia elevat populos.
Vox populi, vox insaniae.
Unius peccata viri populus luit omnis.
Leo rugiens et ursus esuriens, princeps impius super populum pauperem.
Ibi pote valere populus, ubi leges valent.
Tamdiu a periculo aberit populus, quamdiu sciet ferre frenos.
Advocatus et non latro: res miranda populo.
Amor populi praesidium regis.