Fear, dread, fright, alarm, dismay, consternation, panic, terror, horror, trepidation denote the distressing or disordering agitation which overcomes one in the anticipation or in the presence of danger.
Fear is the most general term; like dread, it implies apprehension and anxiety, but it also frequently suggests a loss of courage amounting to cowardice.
Fright implies the shock of sudden, startling, and usually short-lived fear; alarm suggests the fright which is awakened by sudden awareness of imminent danger.
Dismay implies deprivation of spirit, courage, or initiative, especially by an alarming or disconcerting prospect.
Consternation heightens the implication of prostration or confusion of the faculties.
Panic is overmastering and unreasoning, often groundless, fear or fright.
Terror suggests the extremity of consternation or dread.
Horror adds the implication of shuddering abhorrence or aversion, for it usually connotes a sight, activity, or demand rather than a premonition as a cause of fear.
Trepidation adds to dread the implication of timidity, especially as manifested by trembling or by marked hesitation. It is often used for a polite pretense of fear or timidity.