There are several antonyms for the phrase 'up the hilt,' which means to the maximum or fullest extent possible. Some of these could include 'barely scratching the surface,' 'just skimming the top,' or 'just barely getting started.' These antonyms imply that the task or goal has not been fully achieved and that there is room for improvement or more effort is needed. Other antonyms could be incomplete, inadequate, or insufficient, implying that the task or goal has not been fully accomplished. In conclusion, knowing the antonyms to 'up the hilt' can help to understand the context of the phrase better and communicate more effectively.