This is the 3179th most frequent Japanese word.
古き
"古き" means "old" or "ancient."
In this sentence, '古き' is used as an adjective to describe 'friends' (友), emphasizing their long-standing relationship or reminiscence of the past associations.
古き友との再会は特別な瞬間でした。
The reunion with old friends was a special moment.
Here, '古き' augments '都' (capital) to convey the historical and aged charm of a location once prominent or historically significant.
古き都の風景は美しい。
The scenery of the old capital is beautiful.
In this example, '古き' modifies '書物' (books), indicating the temporal nature and the antiquity of the texts, associating them with timeless or traditional knowledge.