This is the 7299th most frequent Japanese word.
乗っかっ
"乗っかっ" means "to get on, to ride, or to be on top of something."
Here, the word '乗っかっている' conveys being situated or positioned on top of something, indicating the cat's location on the sofa.
猫がソファーに乗っかっている。
The cat is perched on the sofa.
In this context, '乗っかって' implies leveraging or building upon someone else's idea or suggestion.
彼のアイデアに乗っかって、新しい計画を提案した。
I built upon his idea and proposed a new plan.
Here, '乗っかって' is used metaphorically to mean continuing or going along with a humorous statement or situation.