Green’s Dictionary of Slang

bullers n.

[f. a brandname]

(N.Z.) gumboots.

[NZ]McGill Reed Dict. of N.Z. Sl. 37: bullers Gumboots, from a brandname for a low-top, lace-up variety popular in bush country, usually cut down to lighten them, the laces replaced with wire and holes made in them to drain water.