Australian colloquial term, a euphemism for swearing, usually and specifically referring to the word 'fuck' being uttered at inappropriate times, or to politely avoid using the word 'fuck' at inappropriate times.
In 1975, during a live reading of a commercial for hair products on his eponymous show, Australian entertainer Graham Kennedy imitated the sound of a crow. No, I have no idea how crows came into it. It was live television, and you know what they say about the past being a foreign country? Live television in the 1970s was definitely a foreign country.
Anyway, Kennedy - who had been a stalwart of Australian television since it began - made a crow sound on live television. What do crows sound like? They sound like this: 'faaaaaaaaaaaark! faaaaaaaaaaaark!'
The incident led to a temporary glitch in Kennedy's career, as the powers that be decreed that his show must be pre-recorded; and coined the term 'crow call'.
Example 1: 'fuck' being used inappropriately
"I tripped on the power cable, dropped the whole plate of cakes, and crow called in front of a roomful of old ladies. I was so embarrassed!"
Example 2: avoiding the use of the word 'fuck'
"Oh yes, Nemosyn talks like she grew up in a shearing shed. Crow calls after every second word!"