The term 'become friendly' can be summarized by three crossword solutions: THAW (4 letters), ECO (3 letters), and USER (4 letters). THAW is a verb meaning to become or cause to become less cold, while ECO is an abbreviation for ecology, the study of the relationships between organisms and their environment. Finally, USER is a noun referring to someone who uses or operates something, such as a computer or a device. Together, these three words suggest that becoming friendly involves thawing out a relationship, understanding the environment in which it exists, and being a USER of the relationship.