Because modern Russian (современный русский язык) only emerged as recently as the 19th century, a lot of what’s considered Russian literary canon is easily understood by Russian speakers today. However, there are a few words that have changed their meaning over the last centuries. Do you know the old meaning of the following words?

Живот

Живот currently refers to one’s stomach, as in “abdomen.” Stomach the organ is called желудок.

Когда́ у меня́ боле́л живо́т и́ли сдира́лась ко́жа на коле́нке, мне о́чень хоте́лось знать, всем ли быва́ет так бо́льно.
When I had a stomach ache or scraped my knee, I really wanted to know if it hurt everyone this badly.
[Зинаида Синявская. Пазлы // «Сибирские огни», 2013]

However, this word used to mean “life” (cf. жить — to live), as is still the case in many Slavic languages.

Вельмо́жа оди́н приговори́л ко сме́рти одного́ своего́ нево́льника, кото́рый, не ви́дя уже́ наде́жды ко спасе́нию своего́ живота́, зача́л брани́ть и проклина́ть вельмо́жу.
A nobleman condemned one of his slaves to death, who, not seeing any hope for saving his life, started scolding and cursing the nobleman.
[Екатерина II. Полемика с Новиковым (1769)]

Глагол

You may know this word from Russian grammar lessons as “a verb.”

Членоразде́льно и отве́тственно Ми́ша выгова́ривал лишь существи́тельные и глаго́лы.
Misha could only pronounce nouns and verbs clearly and responsibly.
[Сергей Довлатов. Заповедник (1983)]

However, it used to refer to any word; this usage is now bookish or obsolete. Based on a quote from Pushkin’s poem, people will ironically say “глаголом жечь сердца людей” (“to set people’s hearts on fire with words”) referring to someone passionately advocating something.

Красный

Красный currently means “red.”

Большинство́ млекопита́ющих не отлича́ют кра́сный цвет от зелёного.
Most mammals can’t distinguish between red and green.
[Александр Зайцев. Загадки эволюции: Краткая история глаза // «Знание — сила», 2003]

As you may know, this word used to mean “beautiful,” hence Red Square (Красная площадь) — the actual pavement is gray and the Kremlin walls used to be painted white. This sense can be seen in such sayings as “Не красна изба углами, а красна пирогами” (literally, “A house is not beautiful because of its corners; it is beautiful because of its pies,” meaning that the hospitality and atmosphere matter more than how fancy a place is).

Неделя

Неделя means “week” now, but it used to mean “Sunday.” That is still the case in Bulgarian. You can see how не делать means “not to do,” which makes sense for a day off. This also explains why Mondays are called понедельник — the day after Sunday.

Всегда́ прия́тно получи́ть но́вый автомоби́ль, хоть и на неде́лю.
It’s always nice to get a new car, if only for a week.
[Андрей Колесников. Бублики Мондео (2002) // «Автопилот», 2002.01.15]

Лето

We all know лето as “summer.”

Кому́ охо́та всё ле́то просиде́ть в кла́ссе?
Who feels like sitting in a classroom all summer?
[Европейские каникулы (2002) // «Домовой», 2002.04.04]

However, лето used to mean “a year.” This can be seen in the archaic expression “в лето Господне,” meaning AD or CE (cf. “anno Domini”). The current equivalent of this expression is нашей эры, abbreviated as н.э. In addition, the genitive plural of “год” is “лет.”

Над свои́м законопрое́ктом я рабо́таю уже́ не́сколько лет.
I’ve been working on my bill for several years.
[Игорь Пылаев. Число избранных (2003) // «Еженедельный журнал», 2003.04.08]

Have you seen any of these words used in their old sense?