Gooseberry

noun

1. A fruit, Ribes uva-crispa, related to the currant.

   "We had a good haul of gooseberries from our bushes this year."

2. Any other plant or fruit in the subgenus Grossularia, distinguished from currants by bearing spines, including Ribes hirtellum, the American gooseberry.
3. Any of several other plants that are not closely related but bear fruit in some way similar:
4. (British slang) A chaperone.
5. An additional person who is neither necessary nor wanted in a given situation.

   "Robert and Susan were so in love with each other that nobody could go near them without feeling like a gooseberry."