leading (n.1) Look up leading at Dictionary.com
"lead work; lead covering or frame of lead," mid-15c., from lead (n.1).
leading (n.2) Look up leading at Dictionary.com
mid-13c., "a bringing by force," from present participle of lead (v.1). Meaning "direction, guidance" is from late 14c. As an adjective, "directing, guiding."