iceberg (n.) Look up iceberg at Dictionary.com
1774, partial loan-translation of Dutch ijsberg, literally "ice mountain," from ijs "ice" (see ice (n.)) + berg "mountain" (see barrow (n.2)). An earlier term was sea-hill (1690s). Phrase tip of the iceberg, in a figurative sense, first recorded 1962. Iceberg lettuce attested from 1893.