noun
coward; timid person; scaredy-cat
Describes a person who is easily frightened or lacks courage. Often used in a teasing or self-deprecating way.
弟は怖がりで、暗い部屋に一人で入れない。
My younger brother is a scaredy-cat and can't go into a dark room alone.
私は怖
I'm a coward, so I never watch horror movies.
怖い is an adjective meaning 'scary' or 'frightening', while 怖がり is a noun for a person who gets scared easily.
臆病者 is a more formal or literary term for 'coward', whereas 怖がり is colloquial and often carries a softer, teasing tone.
Derived from the adjective 怖い (scary) with the suffix がり, which indicates a tendency or disposition. The exact historical derivation is straightforward.