"Dost it" is an archaic phrase that means "do you." There are many modern synonyms for this phrase that are commonly used in English today. Some of the most popular alternatives include "do you," "are you," "can you," "will you," and "would you." These phrases are used to ask questions and to get clarification on a particular topic. Other synonyms for "dost it" may include "doth," "doest," and "do ye." These old-fashioned phrases are rarely used in today's English, but they can be useful for adding a touch of old-world charm to your writing or speech.