One way to hold meditative: attention has turned away from the room and gone inward, and the body has gone still because of it. From outside you only see the stillness. What the word adds is that the stillness has something going on inside it. Where the two meanings part is what that something is - one is a mind slowly turning one thing over, the other is a mind deliberately putting things down.
From the word’s history
The evidence in hand says only that the word was borrowed from Middle French meditatif. It does not trace the form any further back, so no line is drawn from a root to the modern picture here.
手上的字源資料只說它借自中古法文 méditatif。再往前的路線這份資料沒有提，所以這裡不從字根去推今天的畫面。
Wiktionary entry for 'meditative', etymology_text supplied in the evidence packet: 'From Middle French méditatif.'
登入就可以看每一支怎麼連回核心畫面。