Grand achievement is a phrase that describes a significant accomplishment that an individual or group has achieved. If you are looking for synonyms for this phrase, consider words such as triumph, milestone, victory, accomplishment, breakthrough, success, progress, or attainment. Each of these words speaks to the sense of accomplishment that comes with achieving something great. Other synonyms to consider include conquest, accomplishment, advancement, masterstroke, and culmination. Whether you are talking about a personal or professional achievement, using these descriptive words can help you communicate your message effectively and inspire others to achieve their own grand accomplishments.