Someone who cannot be educated or trained.

जिसे शिक्षित या प्रशिक्षित नहीं किया जा सकता।

English Usage: Despite their efforts, the teacher felt that some students were simply ineducable.

Hindi Usage: अपने प्रयासों के बावजूद, शिक्षक को लग रहा था कि कुछ छात्र केवल अज्ञेय हैं।