This word was originally given very short shrift in the Dictionaries of the Scots Language (DSL):
“Slang, a chamber pot”.
Although there are locations given where the word was used in 1939 there are no examples. However, later additions to the DSL show a much earlier example from the 1788 Poems of Ebenezer Picken:
“On yer pow [head] an Envoice light, Het reekan frae some chanty”.
Research must have been so difficult before the advent of all the resources modern technology has made available to us. This is illustrated by the much later date of the next DSL citation for chanty, from Roddy McMillan’s 1974 play The Bevellers:
“..., an’ you’re worryin aboot some stupid article that some half-arsed cowboy'll use for a chanty in the middle o the night”.
The article in question is a bowl.
In the North East the pronunciation and spelling becomes “chunty”, as in this vivid picture of everyday life portrayed by Sheena Blackhall in Wittgenstein’s Web (1996):
“Ah, bit the meenister hidna seen (or mebbe he hid but chuse nae tae notice) auld Bunty Strachan hirplin up an doon stairs frae her mither's bedroom wi a reemin chunty in her hauns ...”.
Finally, an example from the Sunday Herald of March 2021 shows that the term can also be used for a conventional toilet:
“We are devising advertising jingles, based on famous songs, to support local businesses and kickstart the economy once lockdown ends. … [one] ditty could publicise the local plumber, the lyrics now becoming: Someone’s chanty’s leakin”.
(The tune being Some Enchanted Evening from the 1950s musical South Pacific.)
This Scots Word of the Week was written by Pauline Cairns Speitel, Dictionaries of the Scots Language https://dsl.ac.uk.