The word "de-lighting" means to make someone feel disappointed or unhappy. If you are looking for synonyms to use in place of this word, some options include "dismaying", "disheartening", "discouraging", and "displeasing". Other choices might include "frustrating", "upsetting", "unsettling", and "disturbing". Each of these words can be used to describe situations where someone has been let down or feels let down by something. Whether it's a relationship, a job, or any other aspect of life, these synonyms can help you communicate your disappointment and frustration clearly and effectively.