the small perceptible part of a much larger situation or problem that remains hidden
冰山一角，巨大隐情（或隐患）中显露出来的一小部分
detected fraud is only the tip of the iceberg.已查明的欺诈行为只是冰山一角。
detected fraud is only the tip of the iceberg.
已查明的欺诈行为只是冰山一角。