UK slang dictionary
Noun. 1. A contemptible woman, a 'bitch'. Derogatory, but often used less aggressively, as an affectionate aside, as in 'silly cow', see also 'moo'.
2. A difficult or objectionable task or thing. E.g."It was a cow of a job, and took twice as long as I expected."
IT MEANS THAT PERSON IS DUMB, STUPID-LOOKING , AND SLOW TO ACT!
If you looked at a cow's face, it looks dumb and stupid, chewing the cud all day and staring at you as if it couldn't care what happened to the world!
Interestingly, at one time England, France, and adjoining Spain hated one another.
the British used abuses like : "She is such a cow!"
The French abused by saying " La vache espagnol!" ...... The Spanish cow!