Green’s Dictionary of Slang

lord mayor n.1

[on pattern of alderman n. (5); citizen n. (1); gentleman n.: smaller and larger versions of the tool]

[late 19C–1950s] a large crowbar.

SE in slang uses

In compounds

lord mayor’s coal (n.)

[mid-19C] a piece of slate.

lord mayor’s fool (n.) [pvb ‘like My Lord Mayor’s fool, full of business and nothing to do’]

[mid-19C] ‘a personage who likes everything that is good, and plenty of it’ (Hotten 1864).