https://en.wiktionary.org/wiki/連声
daijr: 二つの語が連接するときに生ずる音変化の一。日本語では，漢語の熟語を中心に始まったもので，唇内・舌内の鼻音（ m ・ n ）および舌内の入声音（ t ）の次に来たア・ヤ・ワの三行の音がマ・ナ・タ行音に変化することをいう。

I think we need to be more specific. Rendaku is also "Japanese sandhi".

@@ -11,0 +12 @@
+<xref type="see" seq="2511530">連音・1</xref>
@@ -13 +14,8 @@
-<gloss>Japanese sandhi</gloss>
+<gloss>sandhi</gloss>
+</sense>
+<sense>
+<pos>&n;</pos>
+<field>&ling;</field>
+<s_inf>e.g. いんえん(因縁) → いんねん</s_inf>
+<gloss>renjō</gloss>
+<gloss g_type="expl">morphological change of an initial syllable of the second kanji under the influence of the historical coda of the first kanji in a word</gloss>

@@ -11,0 +12 @@
+<field>&ling;</field>

the explanation is far too drawn out and encyclopedic.  the note is perhaps passable, but i think the definition itself may suffice

@@ -12,1 +12,0 @@
-<s_inf>e.g. 天皇 as てん + おう = てんのう</s_inf>
@@ -14,1 +13,0 @@
-<gloss>type of liaison of consonants in a Japanese word, particularly within a Chinese compound where the first reading ends in 'n' and the second reading starts with a vowel, the reading of the second character acquiring a leading 'n' or 'm'</gloss>

GG5, 大辞林、広辞苑
http:/ja.wikipedia.org/wiki/連声

As per WP and dicts, this refers specifically to the Japanese phenomenon (sandhi/liaison) (general term for sandhi/liaison is 連音).
This is an unfamiliar and technical phenomenon (found it in dictionary when looking up 親王 and previously seen it in 反応), so I thought it worth an explanation (plus note so can have a Japanese example).

@@ -12,1 +12,3 @@
-<gloss>type of liaison of consonants in a word</gloss>
+<s_inf>e.g. 天皇 as てん + おう = てんのう</s_inf>
+<gloss>Japanese sandhi</gloss>
+<gloss>type of liaison of consonants in a Japanese word, particularly within a Chinese compound where the first reading ends in 'n' and the second reading starts with a vowel, the reading of the second character acquiring a leading 'n' or 'm'</gloss>