outcreep
/ˈaʊtˌkriːp/Definitions
1. verb
to spread or grow outward, especially in a slow and subtle way
“The vines outcrept the garden fence, threatening to overwhelm it.”
2. noun
the act of spreading or growing outward, especially in a slow and subtle way
“The outcreep of the ivy on the ancient stone building was a testament to its age.”