A Ghost...when you see a ghost you are filled with fear and surprise
a + ghast ~ a + ghost; a ghost house is filled with lot of surprises and fear, so we get horrified.
remind aghast as afghanistan _____so horified or appalled
AGHAST<===> à¤¹à¤•à¥à¤•à¤¾ à¤¬à¤•à¥à¤•à¤¾ (pr. \\hakka bakka \\ )[Adjective] Example:She stood aghast at the terrible sight. AGHAST<===> à¤à¥Œà¤à¤šà¤•à¥à¤•à¤¾ (pr. \\bhauNachakka \\ )[Noun]