Meaning:
Lit. “to buy on dash/line” which means on credit. Especially if the action takes place in a small village/block shop and you are really desperate to get what you cannot pay for.
The two obvious cases are food or alcohol. If the proprietor accepts the deal, another line of text is added in a special notebook and summed up below the dash/line. Which is where the expression takes its origin. Your job then is to pay your dues by the beginning of the next month or being denied more credit.
This act is also called “kupować na zeszyt” (“to buy on notebook”). There are more idioms with the noun “kreska/krecha” (the latter being an augmentative form). “Zjechać/zejść na krechę” means to go straight downhill if the correct path meanders while “mieć krechę” means to score negative points, for someone to view negatively what you just did. And the same as in English, “wciągnąć krechę” means to sniff a dose of powdered cocaine.
Examples:
Ferdka “przywitała” Malinowska, która kazała mu natychmiast zwrócić 343,27 zł za browary i flaszki, które Ferdynand kupował “na krechę”.
Pił na umór. Gdy nie miał pieniędzy, kupował na krechę. Ludzie bali się go, więc miał kredyt w każdym sklepie.
Coraz więcej osób zamierza kupić na kreskę sprzęt AGD/RTV albo samochód. I dobrze – mówią eksperci – popyt na kredyty napędza gospodarkę.