1.NounA cyclic organic peroxide; a mixture of mostly the trimer, (((CH3)2CO2)3), (TCAP or TATP), containing a nine-membered ring and the dimer, (((CH3)2CO2)2) containing a six-membered ring; it is a high explosive manufactured from acetone and hydrogen peroxide with the aid of sulphuric acid, and has been used by amateur bomb makers.