1. What does it mean?
찐텐 combines 찐, meaning genuine, with 텐션 in its Korean sense of energy or excitement. It describes a reaction that seems sincerely enthusiastic rather than put on for other people.
Also written or said as 진텐, jjinten
2. The nuance
Calling a reaction 찐텐 is an impression of how it looks or feels, not proof of someone's private emotions. It contrasts with 억텐, where the energy seems forced.
3. Examples
“좋아하는 노래 나오니까 갑자기 찐텐으로 춤추네.”
Your favorite song came on, and now you're dancing with genuine excitement.
“오늘 게임 이겼을 때는 진행자도 찐텐이었어.”
Even the host was genuinely excited when they won today's game.
Sources
Nate News: Korean usage in the press
References support the meaning and usage. Example sentences are written for NoCapWiki.