Why was "tantrum" trending last week?
1815, from the true Simon Pure "the genuine person or thing" (1795), from Simon Pure, name of a Quaker who is impersonated by another character (Colonel Feignwell) in part of the comedy "A Bold Stroke for a Wife" (1717) by Susannah Centlivre, English dramatist and actress. The real Simon Pure is dealt with as an imposter in the play and is believed only after he has proved his identity.
To join; enroll; enlist: They signed up for a course in hands-on interpersonal relations (1903+)
[1895+; origin unknown; found in form sambolio by 1886]