का डर था

was afraid of

→ का
phrase Rare #12,470
was afraid of Used after a noun or verb phrase to say that someone feared it. Literally, it means “fear of … was.”
HI: मुझे देर होने का डर था।
EN: I was afraid of being late.

जिस बात का डर था हमें, वही हुआ।

What we feared would happen has happened.

— Padmaavat (2018)

मुझे उसके मरने का डर था।

I was afraid that he might die.