Obs. or dial. [? Onomatopœic, associated with blow, puff. According to Halliwell, A tin tube through which boys blow peas is in Suffolk called a bluff. Cf. BLOUGHT, BLOUGHTY.] intr. To swell out, become distended.
a. 1722. Lisle, Husb. (1757), 482. Pigs would bluff and swell much with their feeding the first six or seven days.