"A dangling modifier is a word or phrase that modifies a word not clearly stated in the sentence. A modifier describes, clarifies, or gives more detail about a concept" (Purdue University, n.d., para. 1). For example: “The ladies of the church have cast off clothes of every kind and they can be seen in the church basement on Friday afternoons” (First Presbyterian Church of Hamilton, Massachusetts, as cited by Chilton, 2004, Snippets & more snippets, #5). It isn't clear whether "they" refers to the ladies of the church or the clothes.
For more information regarding dangling modifiers, please refer to The OWL at Purdue: Dangling Modifiers and How to Correct Them.
Chilton, S. (2004). Snippets: Some examples of bad writing for your amusement and horror. http://www.d.umn.edu/~schilton/Courses/Snippets.html
Purdue University. (n.d.). Dangling modifiers and how to correct them. Purdue Online Writing Lab. https://owl.purdue.edu/owl/general_writing/mechanics/dangling_modifiers_and_how_to_correct_them.html