Up the wall Bruce Dawe "kettle"-colloquial?! (1 Viewer)

[sy24]

I have a small question, my teacher said in the poem up the wall by bruce dawe that the words "kettle" and "boil" are colloquial terms to give the sense of a domestic scene, how is "kettle" and "boil" colloquial? i thought colloquial meant words that are informal and everyday?!