1. Strictly speaking, a time very long ago in one's past. 2. In more common usage, any excessively long duration, whether spatial or temporal. Example: 1. I've been friends with Kerry since fetus days. 2. Walk all the way there from here? That trip will take fetus days.
FETUS DAYS
Meaning of FETUS DAYS in English
Slang English vocab. Английский сленговый словарь. 2012