Fear

bojaźń

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

lęk

(a phobia; sense of fear induced by something or someone)

niepokój

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

strach

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

bać się

(feel fear about (something))

bać się

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

lękać się

(feel fear about (something))