Meaning
Apprehension, anxious thought, or fear of what may come, the heart's brooding over possible harm.
Literally: thought, consideration, dread
How Iqbal uses it
Andesha is thinking turned anxious, the mind circling a feared future. Iqbal contrasts the timid heart trapped in andesha with the bold self that acts in faith, refusing to be paralysed by dread.