What is another word for "brain"?

Roget's Thesaurus (1911) lists these synonyms for "brain": and, arbitrary, behind, blow, book, boutade, briefly, camel, capriccio, caprice, capricious, captious, chase, cold, contrary, crotchet, crotchety, deuce, die, eccentric, erratic, escapade, est, fad, fanciful, fancy, fantastic, fast, fickle, fit, fitful, flimflam, foolish, freak, freakish, frivolous, full, giddy, gnat, have.