Having clients; served by clients; (archaic) having the status of a client.
From 'client' + '-ed' (adjective-forming suffix meaning 'having' or 'provided with'). This archaic formation appears in historical texts about patron-client relationships.
The past participle 'cliented' is virtually dead in modern English—we'd say 'having clients' instead—but it hints at how every English adjective could once be formed with '-ed' to mean 'possessing this quality.'
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