Where does “old timer” come from?

old timer (English) comes from English Time, from Middle English tyme, from Old French thym, from Latin thymum, from Ancient Greek θύμον, from Ancient Greek θύω, from Proto-Indo-European dʰewh₂- — smoke; mist, haze.

Ancestry of “old timer”, step by step

old timer traces back through two separate lines of ancestry.

via English Time

StepLanguageWordMeaning
1EnglishTimeThe inevitable progression into the future with the passing of present and past events
2Middle Englishtymethyme; time; A specific duration or period of...
3Old Frenchthym
4Latinthymumthyme; accusative singular of thymus
5Ancient Greekθύμονthyme
6Ancient GreekθύωI offer in sacrifice, slay, burn, immolate; I...
7Proto-Indo-Europeandʰewh₂-smoke; mist, haze

via English Old

StepLanguageWordMeaning
1EnglishOldOS grid ref SP7873
2Middle Englisholdold; long extant or existent
3Old EnglishaldAlternative form of eald
4Proto-Germanic*ald
5Proto-Germanicaldazold, grown up
6Proto-Indo-Europeanh₂eltós
7Proto-Indo-Europeanh₂él-to grow, nourish
Every word from Proto-Indo-European dʰewh₂-