掌たなごころの玉たまMeanings1expression, nounapple of one's eyeIdiomatic expression meaning a person or thing that is cherished above all others. Often used for a beloved child or treasured possession. Compare with 掌中の玉.See also: 掌中の珠彼かの女じょは一人ひとり娘むすめを掌たなごころの玉たまのようにかわいがっている。She dotes on her only daughter as the apple of her eye.