The Oxford Thesaurus An A-Z Dictionary of Synonyms INTRO ...

deranged adj. mad, insane, demented, lunatic, unhinged, unbalanced,
berserk, crazy, crazed, psychotic, irrational, non compos
mentis, out of one's mind or senses or head, not all there, of
unsound mind, crack-brained, mad as a hatter or March hare, off
the rails, Colloq touched, dotty, daft, cracked, bats, cuckoo,
Brit potty, US have nobody home (upstairs), out to lunch,
off-the-wall; Slang bonkers, dippy, barmy or balmy, batty,
screwy, loony, nuts, nutty, wacky, bananas, off one's rocker,
off one's trolley, mental, missing a few marbles, not having all
one's marbles, kooky, with a screw loose, Chiefly Brit off one's
chump, Chiefly US (plumb) loco, meshuga: Police said that the
killer was completely deranged and should be approached with
caution.
derelict adj. 1 deserted, abandoned, forsaken, neglected; ruined,
dilapidated, run-down, tumbledown: The council has a scheme for
the renovation of derelict buildings in the inner city. 2
negligent, remiss, neglectful, delinquent, dilatory, careless,
heedless, lax, slack, irresponsible, slipshod, slovenly, Colloq
sloppy: He was accused of having been derelict in his duty.
--n. 3 vagrant, tramp, outcast, pariah, loafer, wastrel,
good-for-nothing, ne'er-do-well, malingerer, vagabond, slacker,
down-and-out, US and Canadian hobo, Colloq US bum: Because of
alcohol, he ended up as a derelict.
deride v. mock, ridicule, scoff (at), jeer (at), laugh (at), make fun
or sport (of), tease, taunt, twit, poke fun (at), make a
laughing-stock (of), sneer (at), scorn, flout, disdain,
pooh-pooh, belittle, diminish, disparage, laugh off, Brit rally,
Colloq knock, Brit take the mickey or micky out of: His
classmates had always derided his attempts at getting anywhere
with the girls.
derision n. ridicule, mockery, raillery, laughter, sarcasm, scoffing,
contempt, scorn, contumely, disrespect; satire, lampoon,
pasquinade, burlesque, caricature, travesty: Her suggestion was
greeted with derision.
derisory adj. mocking, ridiculing, scornful, derisive, disdainful,
contemptuous, taunting, insulting, contumelious, jeering;
sardonic, sarcastic, ironic(al), satirical: He felt crushed by
their derisory laughter.