Ablative

Ablative is a term used in linguistics and other fields to describe processes related to removal, origin, or means. In languages with a system of grammatical cases, the ablative is a case that marks various relations between a noun and other elements in a sentence. Its exact function varies by language, but it is often used to express origin or source (from), separation, means or instrument, and sometimes manner or cause. The term derives from the Latin ablativus, reflecting its association with removal or separation.

In Latin and many related languages, the ablative case is the primary means of expressing instrument or means (for example, gladiō = with a sword), as well as cause or reason, place from which something comes, and time when something happens. In other languages the ablative—or ablative-like functions—may be encoded with postpositions or other cases, but the general idea remains: it marks a relation of source, means, or action.

Outside language, "ablative" is used in science and medicine. Ablative materials are designed to erode or ablate under heat or energy, absorbing heat during re-entry or removing tissue. In spacecraft engineering, ablative heat shields rely on controlled erosion to protect the vehicle. In medicine, ablative therapies (for example, radiofrequency or laser ablation) destroy tissue to treat disease.

Etymology: the term comes from Latin ablativus, named for the role of indicating separation or removal.