The Secret War of Lisa Simpson

Literally 'to straighten oneself', but used figuratively to mean reforming one's behavior or attitude. This figurative sense is the one in play and is not deducible from the literal meaning alone in context.

Refers to a sudden strong craving, especially for food. Frequently associated with pregnancy cravings in Latin American usage, making it carry an implied meaning in context that goes beyond a simple 'craving'.