moonstruck

[moon-struhk] /ˈmunˌstrʌk/
adjective
1.
mentally deranged, supposedly by the influence of the moon; crazed.
2.
dreamily romantic or bemused.
Also, moonstricken
[moon-strik-uh n] /ˈmunˌstrɪk ən/ (Show IPA).
Origin
1665-75; moon + struck
British Dictionary definitions for moonstruck

moonstruck

/ˈmuːnˌstrʌk/
adjective
1.
deranged or mad
Word Origin and History for moonstruck
adj.

1670s, from moon (n.) + struck (see strike (v.)). Cf. Greek selenobletos. For sense, cf. moon (v.). Perhaps coined by Milton.