By surface analysis, лепя́ (lepjá, “to glue”) + -еж (-ež).
лепе́ж • (lepéž) m
- sticking
- layer of plaster, coat
- Synonym: мазилка (mazilka)
- “лепеж”, in Речник на българския език [Dictionary of the Bulgarian Language] (in Bulgarian), Sofia: Bulgarian Academy of Sciences, 2014
- “лепеж”, in Речник на българския език [Dictionary of the Bulgarian Language] (in Bulgarian), Chitanka, 2010