Because Microsoft does not support portability, any executable you find labeled "Microsoft Word Portable" on torrent sites or third-party download portals is almost certainly pirated, modified, or bundled with malware.
True portable software is designed to run from a removable storage device (like a thumb drive) without installing files or registry keys on the host computer. Since Microsoft Word is part of the massive Office suite and deeply integrated into the Windows OS, it does not natively support this format. microsoft word portable