/seuhb duk"sheuhn/ , n.
1. an act or instance of subducting; subtraction or withdrawal.
2. Geol. the process by which collision of the earth's crustal plates results in one plate's being drawn down or overridden by another, localized along the juncture (subduction zone) of two plates.
[ 1570-80; subduction-, s. of subductio pulling up, computation; see SUBDUCT, -ION ]