Thro' is a colloquialism for through, a preposition that denotes moving from one point to another. Synonyms for thro' include across, beyond, by, into, past, through, and via. These words all indicate a mode of traversing a path or reaching a destination. Through and via have a more direct connotation, whereas across and past suggest a movement across a surface or past a physical object. Beyond and into imply a progression towards a goal or an entry into a place. By is often used to describe a mode of travel or the proximity of a location. When choosing a synonym for thro', it depends on the context and intent of the message.