do top of your head (verb) wing it: improvise
Sinonime: crackpot, crank, cuckoo, demoniac, flake, fruitcake, kook, lamebrain, loon,
maniac,
neurotic, nut*,
paranoid,
psycho, psychopath,
psychotic, scatterbrain, schizophrenic, sociopathic
Antonime: sane