The term 'remain alive' can be expressed in three different ways: EXIST (5 letters), SURVIVE (7 letters), and SUBSIST (7 letters). Existing means to have a physical or mental presence, while surviving implies continuing to live despite difficult or dangerous circumstances. Subsisting is similar to surviving, but it also implies having just enough resources to stay alive. Therefore, the term 'remain alive' can be interpreted as existing, surviving, or subsisting.