Sundowning is a term used to describe a decline in cognitive abilities toward the late afternoon or evening. It is a common pattern in senile dementia.
Poor Grandma tends towards sundowning around dusk; she's fairly alert in the morning but gets more confused in the evening.
Summoning the monkey: a euphemism for masturbation.
Originally coined by Liam O'Brien of the Critical Role D&D ensemble, and subsequently (maybe) made canon by DM Matt Mercer's explanation that summoning the monkey is the past time of many a wizard in their early years of training.
Sam: Have you seen Liam?
Laura: He's in the bathroom, probably summoning the monkey.
Sam: Thanks, I think I'll join him.
1)To perform a special move in the Square game Final Fantasy X-to summon Aeons; creatures under the character Yuna's command.
2)A little known slang term for a method of female masturbation involving stimulation of the sexual organs by use of the "rumble" feature on a PS2 controller. This can be achieved through a variety of games, but most commonly Final Fantasy X, as the rumble feature is especially strong when Aeons are summoned.