In a lingering way: slowly, and as if you do not want to stop or leave. You look lingeringly at a place you will miss. You kiss lingeringly. The idea is the same as lingering — something lasts longer than the tidy moment — but this form tells you how the action is done. It is a rather bookish, even slightly old-fashioned adverb; in everyday talk people more often say slowly, for a long time, or as if she didn’t want to go. You will meet it in stories more than in conversation.