Between Vivi and Isangila, we traveled in a narrow valley parallel with the chasmic trough of the Congo.
1590s, "deep crack in the earth," from Latin chasma, from Greek khasma "yawning hollow, gulf," related to khaskein "to yawn," and thus to chaos. In English in 17c. often spelled chasma. Figurative use from 1640s. Related: Chasmal; chasmic.