iceberg /ˈʌɪsbəːɡ 
/ ▸ noun a large floating mass of ice detached from a glacier or ice sheet and carried out to sea. – PHRASES the tip of the iceberg (also the tip of an iceberg)
the small perceptible part of a much larger situation or problem that remains hidden: the plastic that can be seen and cleaned from the shore is just the tip of the iceberg.
– ORIGIN late 18th century: from Dutch ijsberg, from ijs ‘ice’ + berg ‘hill’.
EnglishOxford Dictionary of English
