I don't think there's a direct translation of "ironic" in Tagalog and even if there is, I'm pretty sure nobody uses it. For the word "ironic", practically all Filipinos use... wait for it... "ironic". ;)
The Philippines is heavily influenced by the 'western world' that it's more acceptable to use common English words than Tagalog. In fact if you go here, you'd very rarely hear anyone use the greeting 'Magandang umaga' instead people say, 'Good morning."