Which philosophical terms do you think do more to obscure than clarify?
Some terms are ambiguous in ways that invite (unintentional) equivocation, e.g. 'autonomy' and 'intrinsic value'. While safely usable in some contexts, I think it's often preferable to replace these vague terms with whatever more precise understanding you have in mind.
(I should add: not all polysemous words are problematic. There are a bazillion different "internalisms" and "subjectivisms" in common use, but equivocation is rare enough, and -- as I note here -- there may not be any better terms available.)
Other terms are simply badly chosen, or have misleading connotations, e.g.:
(1) "Possible worlds" are really possible states of the world, or world-descriptions. Relatedly, talk of truth "at" a world might be better stated as truth "according to" a world-description.
(2) Moore's use of "naturalistic fallacy" to describe normative reductionism is, I think, a doubly intolerable usage. First, it usurps a far more intuitive alternative usage, namely, denoting the fallacious move from "X is natural" to "X is good". Second, Moore's usage isn't even sensible in its own right, since his target isn't really naturalism per se. You could just as well have a supernaturalist version of normative reductionism, as per (certain versions of) Divine Command Theory. (Besides, it's awfully tendentious to call the very statement of your opponent's position a "fallacy".)
Can you think of any further suggestions (for either list)?