mood, mooed

Mood or mood means an emotional state, or the emotional quality of a work of art or music--
Don't talk to him; he's in a bad mood.
The mood of the piece is lively and cheerful; you are playing it like a dirge.

Mooed or mooed ( rhymes with mood ) is the past tense of "moo", meaning, when said of a cow, to low or make a noise--
The poor cow mooed at every passing car; she didn't like the city.
The cow mooed each morning to wake up everyone on the farm.

Now that you know that, you can say--
"His mood was hostile, until the old cow mooed at him and made him laugh."

Note--not to be confused with "mewed", the past tense ( yesterday, or some time ago ) of "mew", meaning, said of a cat or kitten, to make a crying or high-pitched noise--
The cat mewed loudly when she saw the can of food.