Noun - A sexual or romantic partner who is very physically clingy. Someone who requires a great deal of physical and emotional
attention. Like a
koala bear clinging onto a eucalyptus tree.
Verb - to overly attach yourself to another person. To demand physical attention and contact on a frequent (and often tiresome) basis.
She was a real
koala bear, clinging on to him every time he tried to get anything
done.
She would
koala bear him the minute she walked through the door.