1) Alight from 2) Beat in the joust 3) Come down 4) Defeat at jousting 5) Defeat in a joust 6) Descend 7) Dislodge an equestrian 8) Dislodge from a saddle 9) Dismount 10) Dismount from a steed 11) Fall 12) Get down 13) Get off 14) Go down 15) Handicap Richard III 16) Knock from the saddle 17) Knock off at a Ren Faire 1) Dislodge 2) Unseat 
• (v. t.) To throw from a horse; to cause to dismount; also, to take a horse or horses from; as, to unhorse a rider; to unhorse a carriage.
[v] - get off (a horse)
to cause to fall from a horse, as in battle; dislodge from the saddle: Sir Gawain unhorsed the strange knight. · to defeat; overcome; dislodge, as from a position or office: His vigorous campaign unhorsed his adversary.