Sankoku and Meikyo have [form] for sense 1
GG5, Sankoku, 岩波 生物学辞典 第4版, etc. have sense 2

Google N-gram Corpus Counts
╭─ーー─┬────────┬───────╮
│ 鋸歯 │ 55.939 │100.0% │
╰─ーー─┴────────┴───────╯

https://furigana.info/w/鋸歯
読み方	    割合
ーーーーーーーーーーー
きょし	    71.4%
きよし	    14.3%
のこぎりば   14.3%


のこば is only in koj and big nikkoku, really an abbreviation of のこぎりば. Dropping

Restriction on sense 2 is needed

@@ -13,3 +12,0 @@
-<r_ele>
-<reb>のこば</reb>
-</r_ele>
@@ -17,0 +15 @@
+<misc>&form;</misc>
@@ -18,0 +17 @@
+<gloss>saw teeth</gloss>
@@ -20,0 +20,6 @@
+<sense>
+<stagr>きょし</stagr>
+<pos>&n;</pos>
+<field>&bot;</field>
+<gloss>serration (of a leaf)</gloss>
+</sense>