The legal term apportionment (French apportionement; Med. Latin apportionamentum; derived from Latin portio, share) means distribution or allotment in proper shares.
It is a term used in law in a variety of senses. Sometimes it is employed roughly and has no technical meaning; this indicates the distribution of a benefit (e.g. salvage or damages under the Fatal Accidents Act 1846, ยง 2), or liability (e.g. general average contributions, or tithe rent-charge), or the incidence of a duty (e.g. obligations as to the maintenance of highways).
In its strict legal interpretation apportionment falls into two classes: "apportionment in respect of estate" and "apportionment in respect of time."
Read more about Apportionment: Apportionment in Respect of Estate, Apportionment in Respect of Time