Sentence:  But in what archaeologists describe as one of the most shameful instances of <WSD>'brandalism</WSD>' seen in Britain, Channel 4 executives stand accused of defiling the oldest hill-chalk carving in Britain. 
Meaning of the word marked with <WSD> tags:  The encroachment of ads, logos, and other types of corporate branding into public and traditionally non-commercial spaces, or the dissemination of corporate messages through methods or mediums not typically used for marketing purposes.