leading
n.n. most important, successful, or ahead of others in a group. You use this to describe someone or something that is at the top of their field.
n. occupying the most prominent or influential position within a specific field, group, or competition.
She is a leading expert in modern history.
The company is a leading manufacturer of electric cars, holding the largest market share in the country.
As a leading figure in the civil rights movement, he spent decades advocating for legislative changes that would ensure equal protection under the law for all citizens.
From Middle English ledinge, ledynge, ledand, ledande, ledende, from Old English lǣdende, from Proto-West Germanic laidijandī, from Proto-Germanic laidijandz, present participle of Proto-Germanic *laidijaną (“to lead”), equivalent to lead + -ing. Compare West Frisian liedend, Dutch leidend, German leitend, Swedish ledande, Icelandic leiðandi.
From Middle English leding, ledyng, ledinge, ledunge, equivalent to lead + -ing. Cognate with Dutch leiding (“conduit, leading, guidance, leadership”), German Leitung (“line, conduit, cable”).
From Middle English leedynge, equivalent to lead (chemical element) + -ing; so named because in metal typesetting (letterpress and hot metal typesetting), pieces of lead (slugs, strips, blocks, etc) were often the mechanical means of producing the gap.
Typically placed before the noun it modifies; functions as an attributive adjective.