a unit of one hour's work by one person's thumbs or fingers, especially within the context of interacting with a smartphone touch screen
The number of thumb-hours spent on cell phones and tablet computers has skyrocketed in the last few years.
Thumb licker: (noun) a person who puts both of their thumbs in their own mouth then shoves them up their partners,friends, peers, ect. asshole then licks their thumbs again.
Tyler is on that freak shit he's a Thumb licker.
While having Doggystyle sex with your significant other you place your thumb in her asshole. There for placing "The Thumb in the Plum."
Jill was riding my ass all day about the chores I hadn't gotten to yet, so when we had sex later that night I put "The thumb in the plum."
Thumbs up means they are in love with you
Did you see Stephanie do thumbs up to me?
I think she loves me