Both phrases amount to the same thing: the person spoken of is vacant & stupid, like τοὔστριψε ἡ βίδα. There are many phrases in English, describing such a person. This is a collection:-
a sandwich short of a picnic
a few beers short of a six-pack
one brick short of a load
not playing with a full deck [of cards]
to have bats in the belfrey
to have kangaroo loose in the top paddock
as crazy as a sack full of ferrets
out to lunch
as nutty as a fruit cake
as mad as a hatter
the lift doesn't go to the top floor
the lights are on, but nobody's home/upstairs
to have a screw loose
not the sharpest knife in the drawer
not hitting on all six cylinders
not the sharpest tack in the box
a few fish short of a hatstand
a few penguins short of a lawnmower
-All she does is watch TV & say 'Really, omg, he is, like, drop dead gorgeous!'
-I think the lady down the road is a few sandwiches short of a picnic — you often hear strange bangings at odd hours in the morning.
-That guy might be one card shy of a full deck — he thinks that substitute sugar is really a government tracking system
a) How many common Greek equivalents can colleagues think of &
b) Could anyone translate into Greek the above sample sentences marked in bold letters?