Which word denotes a person who is excessively eager to deliver unrequested or unwanted help?

The term that describes a person who is excessively eager to deliver unrequested or unwanted help is "officious." This word conveys a sense of being overly assertive in one's offering of assistance, often in situations where such help is neither requested nor welcomed. An officious individual typically oversteps boundaries, intruding into matters that do not require their involvement, and can come across as intrusive or meddlesome.

In this context, the word effectively captures the behavior of someone who imposes their help upon others, which aligns perfectly with the definition provided in the question. Understanding this term can enhance a reader's ability to recognize and describe similar behaviors in various social situations.