In transitive terms the difference between lumber and trail
is that
lumber is to load down with things, to fill, to encumber while
trail is to show a trailer of (a film, TV show etc.); to release or publish a preview of (a report etc.) in advance of the full publication.
As nouns the difference between lumber and trail
is that
lumber is wood intended as a building material while
trail is the track or indication marking the route followed by something that has passed, such as the footprints of animal on land or the contrail of an airplane in the sky.
As verbs the difference between lumber and trail
is that
lumber is to move clumsily while
trail is to follow behind (someone or something); to tail (someone or something).
As a proper noun Trail is
a city in British Columbia.