hireling comes from Old English hȳrling, from hȳr ('hire, wages, payment') + the diminutive/agentive suffix -ling, often with a disparaging connotation. Morphologically, the ending is part of the etymology: the suffix is attached to the older base named in the history, producing a later English derivative. In present English, the noun sense is "a person who works only for pay, with implied lack of loyalty", so the historical development ends in a clearly identifiable modern dictionary use. The same base also appears in related forms such as hire and hirer. Its semantic neighborhood includes mercenary, employee, lackey, and henchman, which helps locate the modern sense without adding a separate etymological claim. The named historical forms include Old English hȳr and Proto-Germanic *hūzijō.