Normal swell, which refers to a gentle and gradual increase in size or volume, can be described using a variety of synonyms. Some of these include gradual expansion, steady growth, slow rise, gentle increase, and measured enlargement. Other similar phrases could include moderate augmentation, slight expansion, and incremental growth. Context is important in selecting the most appropriate synonym for normal swell, as different words may convey slightly different nuances in meaning or emphasis. Nevertheless, any of these terms should express the idea of a smooth and consistent increase over time, rather than a sudden or dramatic change.