nonsensical

US /ˌnɑːnˈsen.sɪ.kəl/
UK /ˌnɑːnˈsen.sɪ.kəl/
"nonsensical" picture
1.

having no meaning; making no sense

:
His argument was completely nonsensical and illogical.
The comedian told a series of nonsensical jokes that still made everyone laugh.