Fear

hræðsla

(uncountable: emotion caused by actual or perceived danger or threat)

uggr

(uncountable: emotion caused by actual or perceived danger or threat)

ótti

(uncountable: emotion caused by actual or perceived danger or threat)

hræðask

(feel fear about (something))

ugga

(feel fear about (something))

óask

((used with for) to worry about, to feel concern for, to be afraid for)