a.d.da - not in PED, not in Cone's Dictionary

Dear Friends,

Back on the list after moving back to my home monastery south of Chiang Mai.  I
am working again on the Jataka Commentary, and I've encountered a few problems.
   The latest one has me stumped.  Here's the passage:

atha ne pa.n.dito ''aha.m vo a.d.da.m dhammena vinicchinissaami, .thassatha me
vinicchaye''ti pucchitvaa

The problem word is a.d.da.m, as it doesn't appear in the PED, and I'm told it
is also not in Cone's new dictionary.  I found at least one other use of the
word in the canon in a compound with "kara.na", where it seems to mean "council"
or "court" or "decision", but I can't figure out the derivation:

maa me bhonto a.d.dakara.ne nisinnassa antarantaraa katha.m opaatetha

"Gentlemen, do not break in and interrupt me when I am sitting in council" -
Walshe (p.731)

MN 2.4.9 Dhammacetiya Sutta

Any help would be appreciated.

Best wishes,

Yuttadhammo (Phra Noah)