also: じさボケ
noun
jet lag
Refers to the fatigue and disorientation caused by traveling across time zones.
海外旅行のあと、時差ぼけで眠れなかった。
After the overseas trip, I couldn't sleep because of jet lag.
時差ぼけがひどくて、会議に集中できなかった。
My jet lag was so bad that I couldn't concentrate on the meeting.
時差 means 'time difference' itself, while 時差ぼけ refers specifically to the physical condition caused by it.
Compound of 時差 (time difference) and ぼけ (dullness, mental fog), from the verb ぼける (to become senile or dull).