› a period during which something reaches its highest level, price, rate, etc.: At its peak, the company was valued at £1.5 billion. Several internet service providers tested in the evening peak failed to deliver the new target for high-speed internet.be above/below the peak of sth The shares have started to recover but are still far below their 12-month peak.hit/reach/rise to a peak Investors were looking beyond the UK market because they feared it might have reached a peak. all-time/record/highest peak Markets are subject to strong peaks and troughs due to economic cycles. → Compare trough noun