Proto-Austric: *tab
Meaning: knock
Proto-Austroasiatic: *tap Austroasiatic meaning: pound
Proto-Austronesian: *tabtab
Austronesian meaning: knock
Proto-Thai: Lao tap slap; ZhT *dap 'beat, strike, fight'
References: Peiros 1989, Ben 228, Peiros 1998, 80.