最終目標	170413 "end goal; final target"
最終的な目標	21086
最終の目標	1793

最終目的	107373 "ultimate goal"
最終的な目的	12581
最終の目的	2290

究極の目標	72730	
究極の目的	37379
究極的な目標	2381
究極的な目的	2276

Just noticed, it looks like we may already have an even-higher n-gram "ultimate goal": 最終目標 and/or 最終目的. Current glossing seems inconsistent and maybe a little arbitrary on these entries though.  Are these "ultimate goals" and "ultimate objectives" or "final goals and final objectives" (and, is there a difference? hmmm).

究極の目標	72730	62.7%　　
究極の目的	37379	32.2%
究極目標	3502	3.0%
究極目的	2421	2.1%

In sankoku's entry for 究極, the example usage us 「ーの目的」。(ie. it's common)　N-grams show that 究極の目標 and 究極の目的 are far more common than the contracted forms, but the full forms are not in jmdict, so I can't xref them.

I see gg5 and eij cited, but no kokugos (and google doesn't give me one).

This is one of these cases where I find the entry distracting/misleading as a Japanese learner.  Yes, this term means "final aim".  But the better way to *say* final aim is "究極の目的".

Alternatively, I wouldn't object to creating 究極の目的 and 究極の目標 and xref'ing them together as a sign of relative frequency.  It's a super-common, but also somewhat obvious-looking. Probably no one would think to actively search a dictionary for "final aim", you'd just encounter them by chance (as I have).  Otherwise they seem to fail most basic tests for entry.

If you see 窮極目的in the wild, the meaning is self-evident from 窮極+目的.　

For my part, I'm replacing my flash card for 究極目的 with 究極の目標/究極の目標.  These seem useful enough to me to study.  But not sure any of these belong here.

gg5, eij

'extreme purpose' is rather odd

@@ -5 +5 @@
-<keb>窮極目的</keb>
+<keb>究極目的</keb>
@@ -8 +8 @@
-<keb>究極目的</keb>
+<keb>窮極目的</keb>
@@ -15 +15,3 @@
-<gloss>extreme purpose</gloss>
+<gloss>final aim</gloss>
+<gloss>final end</gloss>
+<gloss>supreme end</gloss>