That’s a mouthful, isn’t it? If something is agathokakological it means it’s made up of both good and evil. Think Spike from Buffy the Vampire Slayer or Darth Vader.
Agathokakological is a combo of the Greek roots agath- (which means good), kako- (which is a variant of cac-, and means, you’ve guessed it, bad) plus -logical (which is a suffix based on logos, meaning word). It was probably coined by Robert Southey, the least famous of the Lake Poets (Wordsworth and Coleridge being much more well known). Southey loved inventing words (the OED has him as the creator of almost 400) but, unlike other well-known word inventors, very few of his have survived to the modern day. This isn’t particularly surprising as several of them seem to be as hard to say/spell as agathokakological. Exhibit 1: batrachophagous which means ‘frog-eating’. What?
In 1813 Southey became poet laureate after being bigged up by his pal Sir Walter Scott (he of Ivanhoe and Rob Roy fame). Not because he was nice, but because Scott didn’t want to do it – he described it as a ‘poisoned chalice’ and said that previous holders had ‘churned out conventional and obsequious odes on royal occasions’. Ouch. In 1837, while being poet laureate and presumably churning out those crappy odes, Southey got a letter from a then-unknown young lady named Charlotte Brontë, asking for some advice on her poems. He praised Brontë’s writing but told her she shouldn’t give up the day job stating ‘Literature cannot be the business of a woman’s life…’. What a dick. And thank goodness she didn’t listen.