Sentence:  One wall advertised a dense muddle of ivy <WSD>overgrowing</WSD> its prefab brick, while a miniature moat with a jerry-built bridge arcing over it snaked around one of the "halls" (as real universities dub their constituent structures). 
Meaning of the word marked with <WSD> tags:  To grow over; (of one thing) to cause (a second thing) to become overgrown (with or by the first thing).