Where does “of the clock” come from?

of the clock (English) comes from English clock, from Middle English clokke, from Middle Dutch clocke, from Old Dutch *clocca, from Proto-West Germanic *klokkā, from Medieval Latin clocca, from Old Irish cloc, from Proto-Celtic klokkos.

of the clock (English): o'clock

Definitions

o'clock

Ancestry of “of the clock”, step by step

of the clock traces back through 3 separate lines of ancestry.

via English clock

Step	Language	Word	Meaning
1	English	clock	An instrument used to measure or keep track of...
2	Middle English	clokke	clock, timekeeping device
3	Middle Dutch	clocke	bell; something bell-shaped
4	Old Dutch	*clocca	bell
5	Proto-West Germanic	*klokkā	bell
6	Medieval Latin	clocca	bell; travelers' cape, literally “a bell”, so...
7	Old Irish	cloc	bell; clock
8	Proto-Celtic	klokkos	bell
9	Proto-Indo-European	klēg-	—

via English The

Step	Language	Word	Meaning
1	English	The	Used before a noun phrase, including a simple noun
2	Middle English	þe	the; Second-person singular pronoun indicating a...
3	Middle English	in	Any kind of accomodation; particularly; A home or...
4	Old English	inn	in; inn
5	Old English	inne	inside, in; indoors
6	Proto-Germanic	innai	within, inside
7	Proto-Germanic	in	in; into
8	Proto-Indo-European	én	in

via English of

Step	Language	Word	Meaning
1	English	of	API; Expressing distance or motion; "Expressing...
2	Middle English	of	of; off; until
3	Old English	of	of, from, off, out of
4	Old English	æf	of
5	Proto-Germanic	*ab	—
6	Proto-Indo-European	apó	—

Every word from Proto-Indo-European klēg- →Every word from Proto-Celtic klokkos →Every word from Old Irish cloc →