lub
LEAST (RESP. GREATEST) OF MAJORING (RESP. MINORING) ELEMENTS OF A PARTIALLY ORDERED SET (NOT NECESSARILY EXISTING IN ALL SETS)
Supremum; Least upper bound; Greatest lower bound; Suprema; Infima; LUB; Lowest upper bound axiom; Smallest upper bound; Infimum; Infima and suprema; Supremum and infimum
Piece of unswallowed food that is unknowingly lodged between someone's teeth.
Before I take the photo, you should get rid of that lub.