The antonyms for the phrase "quick uptake" are slow, sluggish, lethargic, and indifferent. When someone has a slow uptake, it means their ability to comprehend, learn or grasp ideas is limited, and they take a longer time to understand concepts. Sluggish uptake implies a lazy or lethargic approach to learning, whereas an indifferent uptake suggests a lack of interest or motivation in the subject matter. In contrast to quick uptake, a slow or sluggish uptake can be frustrating to both the learners and their instructors, and may require a different approach to teaching or learning. Nonetheless, it is essential to acknowledge that everyone has different aptitudes and abilities when it comes to learning, and the speed of uptake should not be a measure of a person's intelligence or worth.