I'm not sure, but I think the word you're looking for is "metaphor". That's an expression that is not to be taken literally. For example: "He laughed his head off." It doesn't mean that he laughed so hard his head fell off, it just means that he laughed very hard. Another one: "It was raining cats and dogs"(*) just means that it was raining very hard.
On a side note, two different words with different meanings that are pronounced the same are called "homonyms" -- e.g. "bear" and "bare". Two different words that are spelled the same are properly called "homographs" -- e.g. "refuse", when stressed on the first syllable, means "trash" or "garbage"; but when stressed on the second syllable, it means "not to accept". Many homographs are also homonyms.
As a matter of interest: What does "to choke one's chicken" mean? I've never heard that expression before.
(*) Here's a joke involving a metaphor and a homograph. Question: What's worse than raining cats and dogs? Answer: Hailing taxis.
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