deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
A noun is used as a descriptive when it linksto (describes) another noun.
Examples:
kAkam pazyAmi काकं पश्यामि "I see a crow." ← here the noun kAkam काकम् describes no other noun. Maybe it describes a bird, but that's another story.
zuklaG kAkam pazyAmi शुक्लं काकं पश्यामि "I see a white crow." ← here the noun kAkam काकम् describes no other noun, and zuklam शुक्लम् describes kAkam काकम्.
zuklaH kAkaH शुक्लः काकः "The crow is white." ← same here, kAkam काकम् describes nothing, and zuklam शुक्लम् describes kAkam काकम्.