In Uzbek linguistics, historical words (historicisms) are the names of past reality, and in the modern language there is no other lexical unit that could replace them. Historical words are not specific to the vocabulary of the period of the language being described, but are found in the temporary use of a unit specific to the vocabulary of the past period. Historical words, in addition to the nominative function, the function of embodying the era, also serve as a methodological tool. This task is one of the main reasons for preserving historicisms in vocabulary. In the novel by Abdullah Kadiri "Past Days" the period of the Kokan Khanate of the 1950-1960s is described. The author effectively uses historical words to reveal the spirit of the time.