1. Heading in any direction that is conventionally down
   "a downbound channel"; "the downbound train"

See also: down

• unsung
• unsupervised
• unsupportable
• unsupported
• unsupportive
• unsuppressed
• unsure
• unsurmountable
• unsurpassable
• unsurpassed
• unsurprised
• unsurprising
• unsusceptibility
• unsusceptible
• unsuspected
• unsuspecting
• unsuspectingly
• unsuspicious
• unsustainable
• unswayed
• unsweet
• unsweetened
• unswept
• unswerving
• unswervingly