The freelance writer is a man who is paid per piece or per word or perhaps.

Benchley’s line is a characteristically deadpan, self-undercutting definition that turns on its abrupt incompleteness (“or perhaps”). It satirizes the precariousness and improvisation of freelance life: payment schemes are piecemeal (per piece, per word), and even the terms of compensation can feel uncertain or subject to change. The joke also pokes at the difficulty of pinning down what a “freelance writer” is—less a stable profession than a shifting arrangement with editors and markets. By trailing off, the sentence mimics the freelancer’s perpetual negotiation and the sense that there is always another caveat, another rate, or another contingency waiting to be added.