To pour is to flow rapidly in a steady stream, or to cause something to flow. You can pour good coffee into a cup and pour bad coffee down the drain.
You can pour your heart out, pour a cup of orange juice into or out of a cup, or watch the rain pour down while a poem pours from your lips. A jet of water may pour from a spout. Listen to how the water pours in this poem from Lewis Carroll's book, Alice in Wonderland: “How doth the little crocodile / Improve his shining tail, / And pour the waters of the Nile, / On every golden scale!”