sunday express crusader

[striver]

am at a complete loss now for
4 a gypsum(white or black plant by a city)
12 a deceive(large walkway said to charm)
6 d in the air(a student frequently giving up)
can anybody help please
i've got 4 a I_A_ _ _ T _R , 12 a B_G_I_C and
6 d _ _ O_T
I've probably got some letters wrong here

[Aquagility]

4a Alabaster, check your first I

[gen2]

12a beguile

[gen2]

6d aloft

[striver]

thanks aquagility and gen2
this means i've got 4 down wrong i've put idiotic for stupid
i've now got for 4 down a-i-t-e
can you help

[netkey]

Could 4d be asinine for stupid?

[johnalex]

4d agree 'Asinine'
10a Editorial

[striver]

thanks netkey and johnalex
i am so stupid this week