or pancake, phr. (colloquial).Very flat indeed. Also FLAT AS BE BLOWED.
1882. Punch, vol. LXXXII, p. 177, col. 1.
TO BRUSH UP A FLAT. See BRUSHER.
TO PICK UP A FLAT, verb. phr. (prostitutes). To find a client. Fr., lever or faire un miché (miche = bread, from michon = money. Compare BREADWINNER: under MONOSYLLABLE [q.v.]).
1869. GREENWOOD, The Seven Curses of London. On the chance that she will, in the course of the evening, PICK UP A FLAT.