Now Tom was motioning with his hand out, palm down flat, making a small circular motion in mid-air.

汤姆伸出手来，手心平着向下，在空中划了个小圈。

youdao

Scientists had volunteers place one hand, palm down, under a board.And they asked the subjects to guess, by pointing to the board with their other hand, where their hidden knuckles and fingertips lay.

科学家让志愿者们把一只手放在一块板下，手心向下，然后让他们用另一只手隔着板指出板下那只手的指关节和指尖的位置。

youdao

In the end, I turned down Raoul's tempting offer of the Palm Beach trip.

最后，我拒绝了拉乌尔去棕榈海滩旅行的诱人提议。

《柯林斯英汉双解大词典》

Simply set Palm Pre down on top of the elegantly designed Palm Touchstone(TM) charging dock without worrying about connection, orientation or fit.

ENGADGET: for Mobile

In addition, he often used the hand chop, palm-down, and the smooth broad gestures that signal certainty and authority.

FORBES: Body Language Advice for Rick Perry

Research firm IDC says Palm scored 31% of the U.S. smartphone market in 2005, up from 18% in 2004, but competing units from Motorola, Research in Motion and Nokia are breathing down Palm's neck.

FORBES: Magazine Article