On browser, if we want to get the clicking word we can use following Javascript:

var captureWordOnClick = function(containerEl, callback) {
    containerEl.addEventListener('click', function (event) {
        // Get the mouse position relative to the clicked element
        const x = event.clientX;
        const y = event.clientY;

        // Get caret position at the point of click
        const caretPosition = document.caretPositionFromPoint(x, y);

        // If the click is on text, the offsetNode should be a text node
        if (caretPosition && caretPosition.offsetNode.nodeType === Node.TEXT_NODE) {
            // Get the full text where the click happened
            const fullText = caretPosition.offsetNode.nodeValue;

            // Get the clicked word by splitting text around the clicked character
            const offset = caretPosition.offset;
            const words = fullText.split(' ');

            // Find which word was clicked by checking the offsets
            let charCount = 0;
            for (let word of words) {
                if (offset <= charCount + word.length) {
                    // Clean the word by removing punctuation at the end
                    const cleanedWord = word.replace(/[.,!?;:"]+$/, '');
                    callback(cleanedWord);
                    break;
                }
                charCount += word.length + 1; // +1 for spaces
            }
        }
    });
};

Usage:

captureWordOnClick(
    document.getElementById('post-content'),
    (w) => {console.log(w);}
)

The callback function will receive the word and you can handle it it callback function.