kissing cousin

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A distant relative who is known well enough to be kissed when greeted.
• noun One of two or more things that are closely akin.

from the GNU version of the Collaborative International Dictionary of English.

• A cousin sufficiently well acquainted to be greeted with a kiss; a type of kissing kin.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A relatively distant relative who is familiar enough to be greeted with a kiss.
• noun figuratively A similar or related thing.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a more or less distant relative; familiar enough to be greeted with a kiss