un·chal·lenge·a·ble 
(ŭn-chălən-jə-bəl)
(ŭn-chălən-jə-bəl)adj.
Not open to challenge: unchallengeable facts.
un·challenge·a·bly adv.
- long-livedness
- long measure
- long meter
- longneck
- long pepper
- long-playing
- long-range
- long run
- longshore
- longshoreman
- long shot
- long-sighted
- long-sightedly
- long-sightedness
- longsome
- Longs Peak
- longspur
- long-standing
- longstanding
- Longstreet
- long-suffering
- long-sufferingly
- long suit
- long-tailed duck
- long-term