Solemnised is a word used to describe a formal and serious event. There are many synonyms for this word, each with their unique connotations. Some of the most common synonyms include "celebrated," "observed," "commemorated," and "marked." Celebrated is often used in reference to important holidays or milestones, whereas observed implies a more religious or cultural event. Commemorated is often used in reference to events that hold historical significance, while marked can refer to any notable occasion. Other synonyms for solemnised include "honoured," "acknowledged," "recognized," and "applauded," each carrying their unique connotations and nuances. Ultimately, the synonym chosen will depend on the context and the desired tone.