Quirk, fixation, obsession; exhausting hassle; extreme fatigue. An intensely expressive, high-voltage noun derived from ебать. It carries two main slang meanings: 1. a sudden, irrational mental fixation or erratic behaviour (у каждого свой заёб — “everyone has their own weird quirk”); 2. a state of overwhelming, exhausting mental or physical burnout from overwork.
У одной моей знакомой — тоже есть принцип. Точнее заёб. Не давать мужикам чаще одного раза.
One of my acquaintances also has a principle. More precisely a quirk. Never sleep more than once with men.
(Арсен Ревазов, Одиночество-12, 2005)
Вся операция по поимке Бен Ладена показана как персональный заеб одной црушной бабы.
The entire operation to capture Bin Laden is portrayed as a personal quest by one CIA chick.
(Артемий Лебедев @ ЖЖ, 02/2013)

