taru-adjective, adverb taking the 'to' particle
old-fashioned and tasteful; antique elegance
Literary taru-adjective describing something aged and refined, often used for objects, scenery, or artistic works with a venerable, tasteful patina. Rare in modern conversation.
その茶碗は蒼古とした趣がある。
That tea bowl has an antique and tasteful charm.
庭園の石灯籠が蒼古として佇んでいる。
The stone lantern in the garden stands with an air of aged elegance.
Compound of 蒼 (deep blue, old) and 古 (old, ancient). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning of venerable, tasteful age.