The Collaborative International Dictionary of English v.0.48:

Cibol \Cib"ol\, n. [F. ciboule, LL. cepula, cepola, dim. of L.
   cepa, caepa, caepe, an onion. Cf. Chibbal, Cives.]
   A perennial alliaceous plant (Allium fistulosum), sometimes
   called Welsh onion. Its fistular leaves areused in cookery.
   [1913 Webster]