This week's Lower East Side Librarian Library of Congress Subject Heading of the Week for Week 9, March 3, 2010 is another pair:
(C) 150 Nearness spaces [sp2010002044]
450 UF N spaces (Nearness spaces)
450 UF Spaces, Nearness
550 BT Topology
150 Proximity spaces [sp 85108029]
* 550 BT Nearness spaces
* 550 BT Topology CANCEL
Because these terms are so different, as opposed to FAN MAGAZINES and FANZINES!
Proximity space, from Wikipedia: In topology, a proximity space is an axiomatization of notions of "nearness" that hold set-to-set, as opposed to the better known point-to-set notions that characterize topological spaces. [emphasis mine] To be fair, I haven't found a good definition of nearness space.
Runner up:
(C) 150 Compost tea [May Subd Geog] [sp2010002039]
450 UF Tea, Compost
550 BT Fertilizers
Which you'll be glad to know is for plants to drink, not you.