There are several synonyms for the phrase "fill again" that can be used to convey the same meaning. Some of these include refill, replenish, resupply, restock, top up, reload, and recharge. These synonyms refer to the act of adding more of something to replace what has been used up or emptied. They can be applied to various scenarios, such as refilling a glass with water, replenishing a stock of goods, restocking a pantry, or recharging a battery. By using these alternative phrases, writers and speakers can add variety and precision to their language and avoid repetition.