【机】 incipient crack
at the beginning of; early; elementary; first; original
【医】 arch-; arche-; prot-; proto-
crack; rend; split
【医】 cleavage; cleft; crena; crenae; diastem; diastema; fissura; fissure
gap; rictus; rima; rimae; schistasis; schisto-; schizo-