Hourly means happening once every hour. Hourly bulletins, an hourly service, paid hourly.
An hourly service is the base frequency people plan around, and dropping below it changes how a route is used entirely. Hourly pay is by the hour worked rather than by salary, which is the important distinction in employment law. Note that hourly works as both adjective and adverb.
1adjectivehourlyHappening once every hour.
“The nurses made hourly checks on the patient throughout the night.”
hourly is a frequency.
Middle English
houre
English
hour
English, today
hourly
From hour + -ly. hour comes from Middle English houre. From Middle English houre, hour, oure, from Old French houre, from Latin hōra (“hour”), from Ancient Greek ὥρα (“any time or period, whether of the year, month, or day”), from Proto-Indo-European yóh₁r̥ (“year, season”). Akin to Old English ġēar (“year”). a doublet of hora and year. Compare horary. Partly displaced native Old English tīd (“time, hour”), whence Modern English tide.
Etymology from Wiktionary, CC BY-SA