The term 'Gleam Tremulously' can be summed up by the word 'SHIMMER', which has 7 letters. Shimmering is a type of light reflection that occurs when light is reflected off of a surface in a rapid and intermittent manner. This type of light reflection is often seen in the sun reflecting off of water or in a sparkly dress. The term 'Gleam Tremulously' implies that the light is being reflected in a more subtle and delicate way, giving off a soft and gentle glow.