noun

• (category theory) A functor from an index category to another category. The objects and morphisms of the index category need not have any internal substance, but rather merely outline the connective structure of at least some part of the diagram's codomain. If the index category is J and the codomain is C, then the diagram is said to be "of type J in C".
• (crosswording) A crossword grid.
  "Because you have fewer 10- to 15-letter entries in the diagram, you can make judgment calls more quickly by testing out the long ones at the outset."

verb

• (transitive) To represent or indicate something using a diagram.
• (UK) To schedule the operations of a locomotive or train according to a diagram.
  "The timing and diagramming staff, too, were on duty for up to 21 hours devising 80 engine, 60 guards' and 25 carriage working diagrams."