Detruncating is the process of cutting or removing a part of something. Antonyms for this word would be to add or attach something instead of cutting or removing it. Some possible antonyms for detruncating could include "augmenting," "supplementing," "enlarging," "expanding," "growing," or "extending." These words all suggest adding to something rather than taking away from it. For example, instead of detruncating a garden by removing plants, one could augment it by adding new flowers or plants. Similarly, instead of detruncating a project by removing features, one could expand it by including new ideas or elements.