What is of the nature of a quagmire; yielding or trembling under the foot, as soft, wet earth; spongy; boggy. "O'er the watery strath, or quaggy moss." Collins called?

quaggy — Of the nature of a quagmire; yielding or trembling under the foot, as soft, wet earth; spongy; boggy. "O'er the watery strath, or quaggy moss." Collins. (Webster's 1913.)