The article highlights the cognitive and linguistic aspects of Ukrainian humorous discourse during the full-scale Russian invasion, focusing on the process of interference of words of foreign origin. Particular attention is paid to lexemes and their reinterpretation through cognitive patterns, such as availability heuristics, negative thinking, the accessibility cascade, the friend-foe pattern, the effect of contrast and stereotypical expectations. The study reveals a variety of stylistic means of comism that are caused by the interference of words of foreign origin in humorous Ukrainian discourse. The main techniques are irony, allusion, comic innuendo, parallelism, paradox, hyperbole, baphos, gradation, metaphor, and rhetorical figures. These stylistic elements of humor play an important role in creating a comic effect and shaping a humorous statement in wartime. The determined communicative functions of Ukrainian humor fragments relate to maintaining an optimistic moral state, promoting the unanimity of the Ukrainian people in the difficult circumstances of the war, creating a negative image of the enemy, and relieving psychological stress that occurs in people during hostilities, air raids, and shelling. The sample has three American tokens, three English tokens, two German tokens, and one Turkish token, which is duplicated in two jokes. All of them are reinterpreted and receive additional meanings and connotations. Ukrainian humorous discourse during the full-scale Russian invasion of Ukraine is based on topics relevant to the country: political, military, cultural-historical, and social. The systematized use of borrowed words in modern jokes can be seen, and it concerns the current realities of Ukrainians. Humor itself is built on situational circumstances, military aspects, and their consequences for society. The interference of foreign-language lexemes leads to the acquisition of specific words and phrases with new and ambiguous lexical and semantic meanings. Most of the sample, which refers to the military aid of Western countries, interprets the borrowed words in a positive sense; the other part, which concerns Russian realities, gives the constructions negative comic and ironic-humorous meanings.