"deliberate and planned targeting of innocent non-combatants for killing and maiming..." and without any reasonable hope of ever achieving political and military objectives through such action.

Example: If there was any reasonable hope that Palestinian attacks on Israeli civilians would somehow convince all the Israelis to pack their bags, take down the Star of David, abolish the state of Israel, and all move to Europe, America, or to Arab states, then it might be plausibly argued that the attacks weren't "terrorism". But we all know, or at least those among us who are sane, that such attacks accomplish absolutely nothing but to harden the Israelis' resolve, and to bring more punishment down upon the Palestinians. Thus it's also the sheer pointless nature of the attacks on civilians which classifies them as "terrorism".