Final answer:
Barriers are obstructions that interfere with health behaviours, which can include financial, accessibility, preference, or external influences. These can affect health outcomes, such as life expectancy, and are distinct from barriers to entry in markets.
Step-by-step explanation:
The term that fits the description of perceived unavailability, inconvenience, expense, difficulty, or time regarding health behaviours is barriers. Barriers to health can include a variety of obstacles such as economic factors, accessibility issues, personal preferences affecting health and longevity, or external forces that may either positively or negatively influence health outcomes. Examples of these barriers include financial constraints, limited access to healthcare facilities, or the influence of personal choices related to diet, exercise, or tobacco consumption. In contrast, barriers to entry in a market are legal, technological, or market forces that discourage or prevent potential competitors from entering a market, which are also crucial to understand in the field of business.