1. Characteristic of the time of chivalry and knighthood in the Middle Ages
   "the knightly years";
   - chivalric, medieval, mediaeval
    
2. Being attentive to women like an ideal knight
   "His knightly behaviour impressed everyone at the ball";
   - chivalrous, gallant

Sounds like: knights, nightly, nig

See also: courteous, past

Encyclopedia: Knightly