Abstract The case study concentrates on a lexical adaptation of the nouns weblog and blog in the Slovak language. The processes of borrowing and subsequent adaptation are analysed in accordance with the theory of lexical motivation (TLM). Lexical adaptation represents a process on the basis of which a loanword is incorporated into the system of the borrowing language (L2), i.e. serving as an underlying, motivating word for coining new lexemes, and thus generates a nomination family (nomination nest). The concept of the nomination family is based on the understanding of the term word-formation nest, commonly used in derivatology. The nomination family is a cluster of all lexemes (single-word, or multi-word expressions), which are grouped around the initial, underlying, motivating loanword on the basis of formal and semantical relationships. The nomination family of the loanwords weblog and blog is substantial, and includes more than 200 entries. Both initial lexemes (weblog, blog) are taken from English (using the terminology of TLM, the concept of interlingual motivation is employed) while the nomination relationship – abbreviation (weblog → blog) has been transferred from L1 to L2. The word blog is thus polymotivated, its formation can be viewed in a twofold way: (a) as a loanword it has been borrowed from L1 (interlingual motivation), (b) as an abbreviation it has been formed from weblog (abbreviation motivation). A number of entries have been taken over and integrated at the same time (e.g. bloger, bloging, foodblog, foodbloging etc.) into the blog nomination family in the Slovak language. The impact of word-formation is extraordinarily evident in the formation from the word blog, cf. words denoting male and female persons (bloger, blogerka), adjectives (blogový, blogerský), verbs (blogovať), and notably compounds and their derivatives (videoblog, videoblogový, videoblogovať, videobloger, foodblog, foodbloger, foodblogerka, mikroblog, mikroblogovať, mikroblogový, etc.). Even though almost half of derivatives can be classified as nonce-formations, this kind of word-formation manifests a huge potentiality of word-formation motivation in the Slovak language. Moreover, a significant place in the blog nomination family is held by multiword expressions such as politický blog ‚political blog‘, cestovateľský blog ‚travel blog‘. In addition, competition between multi-word expressions and semantically identical compounds (technologický blog – techblog) is rare. A complex notion to be denominated is predominantly expressed either by means of a multi-word expression (finančný blog ‚financial blog‘, knižný blog ‚book blog‘), or a compound (foodblog, mikroblog).