Gerund functioning as an uncountable noun meaning the act of sleeping lightly.
Definitions
The act or state of sleeping lightly. His constant dozing during the lecture annoyed the professor.
dozegerund / present participle Used attributively as a participial adjective (e.g., "the dozing child").
Definitions
Lightly sleeping; in a state of light sleep or drowsiness. She tiptoed past the dozing toddler.