A palaeochannel, or paleochannel, is a remnant of an inactive river or stream channel that has been filled or buried by younger sediment. The sediments that the ancient channel is cut into or buried by can be unconsolidated, semi-consolidated, consolidated or lithified. The word palaeochannel is formed from the palaeo, meaning "old," and channel. It may be synonymous with palaeovalley and palaeoriver.