General Antonyms:
* Clumsily: This is the most straightforward antonym, meaning to move or act awkwardly.
* Awkwardly: Similar to clumsily, but with a focus on lack of grace.
* Ineptly: Lacking skill or ability.
* Ungracefully: Lacking elegance or skill.
More Specific Antonyms:
* Carelessly: If "deftly" means with care and precision, "carelessly" is an antonym.
* Crudely: If "deftly" means with skill and finesse, "crudely" suggests a lack of refinement.
* Roughly: If "deftly" means with precision, "roughly" suggests a lack of accuracy.
The best antonym will depend on the specific meaning of "deftly" in the context of your sentence.