To remand something is to send it back. Remand implies a return. The usual contexts in which this word are encountered are reversal of an appellate decision, and the custody of a prisoner.
When an appellate court reverses the decision of a lower court, the written decision often contains an instruction to remand the case to the lower court to be reconsidered in light of the appellate court's ruling. Cases are also remanded to Federal agencies for reconsideration in disputes over regulation or administrative decisions. See INS v. Ventura.
A prisoner is said to be remanded when she is sent back into custody to await trial.