taru-adjective, adverb taking the 'to' particle
Archaic literary word describing a bleak, lonely, or desolate atmosphere or state. Used as a taru-adjective or adverb with と.
古い小説に「落莫とした風景」という表現が出てくる。
In old novels, the expression 'a desolate landscape' appears.
彼は落莫として、一人酒を飲んでいた。
He was drinking alone, feeling lonesome and dreary.