BTW, just to follow-up – disregard earlier note about “completely withered” – I’d missed a 〜きる（〜切る） on the end (= completely …).

I teetered on the edge of merging with うらがれる. For now I think not, partly because すがれる is "uk", and it is hard to make that work in a merge.

@@ -19,0 +19,1 @@
+<xref type="see" seq="1851650">末枯れる・うらがれる</xref>

most hits for 末枯れる will be for うらがれる.  rearranging (to match all my kokugos except meikyo) for this reason.  potential merge with うらがれる here.

@@ -5,1 +5,1 @@
-<keb>末枯れる</keb>
+<keb>尽れる</keb>
@@ -8,1 +8,1 @@
-<keb>尽れる</keb>
+<keb>末枯れる</keb>
@@ -18,0 +18,1 @@
+<pos>&vi;</pos>
@@ -19,4 +20,11 @@
-<gloss>wither (esp. plants as winter draws near)</gloss>
-<gloss>fade (when something is past its peak and declining)</gloss>
-<gloss>shrivel</gloss>
-<gloss>start to wither</gloss>
+<gloss>to wither (esp. plants as winter draws near)</gloss>
+<gloss>to fade</gloss>
+<gloss>to shrivel</gloss>
+</sense>
+<sense>
+<pos>&v1;</pos>
+<pos>&vi;</pos>
+<misc>&uk;</misc>
+<gloss>to pass one's prime</gloss>
+<gloss>to start deteriorating</gloss>
+<gloss>to begin to decline</gloss>

GG5, 大辞林、広辞苑、新解さん
(Google hits for kanji frequency, all quite uncommon, and GG5 gives examples in kana;
闌れる given in 新解さん)

Read in book for class 『日本語上級読解』 (as before), referring to withered grass in a field in January.

Book glosses it 「すっかり枯れてしまった」 (completely withered), but dictionaries all state “*starting* to wither (as winter approaches)”, or “in the process of withering” instead, so that’s what I’ve put. Given apparent etymology （す＋枯れる）, it might mean “at either end of withering – starting to wither (dicts), completely withered (book)“, but this is pure speculation.

From 牟田口義郎『旅のアラベスク』 (1977), collection of newspaper columns for 朝日新聞.