injudicial comes from in- ('not') + judicial, from Latin iudicialis ('of a court'), from iudicium ('judgment'), from iudex ('judge'), from ius ('law') + dicere ('to say'). Morphologically, the prefixed shape matters: the initial element belongs to the recorded formation and helps explain the modern form's surface analysis. In present English, the adjective sense is "not in accordance with sound judgment or proper legal procedure", so the historical development ends in a clearly identifiable modern dictionary use. The same base also appears in related forms such as judicial, judge, judgment, and judicious, and in derivatives such as injudicially. Its semantic neighborhood includes injudicious, unwise, imprudent, and irregular, which helps locate the modern sense without adding a separate etymological claim. The named historical forms include Latin in-, Latin iudex, and Latin ius.