The word "ex-pended" refers to the act of using up or consuming something completely. As an antonym, "conserved" would be appropriate, indicating the act of preserving or saving something for later use. "Saved" or "stored" can also be used in the same context. "Hoarded" can be considered a negative connotation of conservation, suggesting the excessive or selfish accumulation of something without any intention of using or sharing it. Other antonyms for "ex-pended" might include "maintained," "preserved," and "retained," which suggest the careful and deliberate use of resources, ensuring they are not wasted or exhausted.