The term 'SUB SPREAD' is a combination of two words, 'SUB' and 'SPREAD'. The first word, 'SUB', is a shortened form of the word 'SUBMARINE', which is a type of sandwich that is made with a long roll filled with various ingredients. The second word, 'SPREAD', refers to a condiment or sauce that is SPREAD over the sandwich. The crossword solution for this term is 'MAYO', which is a type of creamy sauce that is often used as a SPREAD on sandwiches.