(a)longprimarily temporal sense; being or indicating a relatively great or greater than average duration or passage of time or a duration as specified“a long life”, “a long boring speech”, “a long time”, “a long friendship”, “a long game”, “long ago”, “an hour long”
(a)longprimarily spatial sense; of relatively great or greater than average spatial extension or extension as specified“a long road”, “a long distance”, “contained many long words”, “ten miles long”
(r)longfor an extended time or at a distant time“a promotion long overdue”, “something long hoped for”, “his name has long been forgotten”, “talked all night long”, “how long will you be gone?”, “arrived long before he was expected”, “it is long after your bedtime”