asustar

to scare, to frighten, to spook; to freak out (somebody), to creep out; to startle; to be scared, frightened; to freak out, to get freaked out, to panic

“Me asusté cuando de la nada, un escarabajo voló hacia mí y se me metió en el pelo.” — I freaked out when out of nowhere, a beetle flew at me and got in my hair.

Either derived from a- + susto (“fright”) + -ar, or less likely from a Latin suscitāre (which would hypothetically make it a cognate with English suscitate). More likely linked to Latin substāre, from sub- + stō . Compare Portuguese assustar.