A person or thing that depends on someone or something else; one who relies on another.
From depend (Latin dependere) plus -er (agent suffix, Old English -ere). The suffix -er creates agent nouns meaning 'one who does X,' so a depender is literally 'one who depends.'
The word 'depender' is relatively rare in modern English, but it appears in legal documents and psychological case studies where researchers need a neutral term for someone in a dependent relationship—it's more precise than 'dependent' when you need a noun.
Complete word intelligence in one call. Free tier — 50 lookups/day.