The car rolled over the twin cows TEN times, decapitating them.
|( が ) ころ＊がる||
|( が ) ころ＊ぶ||
something rolls over; something turns over
convert to new ideology, do an about-face. This is important because most of the freaky looking kids you see on the street will all become housewives and salarimen the exact second they turn ２3. - making TENKOU what we call a "cultural code word."
when a salariman gets transferred to another office, that's tenkin.
I only mention this because most of the Japanese you meet who speak good English, probably one of their parents got tenkin-ed to America / UK, so it tends to come up in conversation.