1. Having the wind against the forward side of the sails
   "the ship came up into the wind with all yards aback"
    
2. By surprise
   "taken aback by the caustic remarks"

Encyclopedia: Aback

• Pseudotsuga macrocarpa
• Pseudotsuga menziesii
• pseudovariola
• Pseudowintera
• Pseudowintera colorata
• PSF
• pshaw
• psi
• psi particle
• Psidium
• Psidium cattleianum
• Psidium guajava
• Psidium guineense
• Psidium littorale
• Psidium littorale longipes
• psilocin
• psilocybin
• psilomelane
• Psilophytaceae
• Psilophytales
• psilophyte
• psilophyton
• Psilopsida
• psilosis
• Psilotaceae