The term 'apartment number' is used to refer to the unique identifier assigned to a specific apartment in a building. The two crossword solutions for this term are TWOC and UNIT. TWOC stands for 'Two Character' and is typically used to refer to the two-digit number that identifies an apartment within a building. UNIT is a more general term that can be used to refer to any individual living space within a building, such as an apartment, condo, or townhouse.