When a person smokes enough marijuana to feel its effects, but not enough to alter competence at regular daily tasks or create a lasting low after the effects have worn off.
Becoming functionally high is a skill that comes naturally for some, and for others takes a long time to develop and master.
Rick: "What the heck would f(x) equal? I hate fucktions!"
Esteban: "Hahahahaha... nice"
Ms. Rod: "What kind of problems are you guys doing?"
Evan: "That, my friends, is called a Freudian slip... haha."