Stricken or afflicted, as by paralysis or other sudden physical disorder, as a result of the supposed malign influence of a planet. Hence: seized by sudden fear, amazement, etc.; panic-stricken; bewildered.
Origin
Early 17th century; earliest use found in Robert Armin (1563–1615), actor and comic writer. From planet + struck, past participle of strike, probably after planet-strike. Compare slightly later planet-stricken and planet-striking.