The term 'BUILD ON' can be broken down into five crossword solutions: DEPEND (6 letters), SPEC (4 letters), LOT (3 letters), ADD (3 letters), and ADDTO (5 letters). The term 'DEPEND' means TO rely on or trust in someone or something, while 'spec' is short for specification, which is a detailed description of a product or service. 'LOT' is a term used TO refer TO a large amount of something, and 'ADD' means TO join or combine two or more things together. Finally, 'addto' is a combination of the words 'ADD' and 'TO', which implies that something is being added TO an existing item or group.