[1] The headword is plural of the neuter noun tumpanon. The glossing synonym is a transliteration of Latin baculum. This entry is out of alphabetical order. Manuscript G has it after 1164 where it would belong; M has it after 1165 but (according to Adler) corrects the order. The present order would be right here and in Hesychius (as LSJ note) if the headword is spelled tu/pana, a form which is guaranteed by the meter at several places in poetry and which would make the etymological point clearer.
[2] From a scholion on Aristophanes, Wealth [Plutus] 476, where the phrase w)= tu/mpana kai\ ku/fwnes occurs; already at kappa 2800. See also Hesychius omega487. For tumpani/zein see tau 1165.