How about cement and concrete. Cement is an ingredient in concrete.
For me as for not native English homonyms are mess. "concrete" is one of first which comes in my head when asked about those words
For concrete we have "beton". That is actually German word and somehow I like how it sounds. Solid
In our language there are a lot of those homonyms either. Like we dont have enough words
Most common mistake is with word "laiks". That means either "time" either "weather". I have noticed people which learns Latvian makes mistake with that very often
And from my professional life - as we do productivity calculations for furniture fabricants we are rooting our mathematics in cycles / min. = pieces / min.
In Latvian "piece" = "detaļa". "detaļa" is very "powerful word, it can be a single piece of some complex item or spare part whatever. And everybody, literary EVERYBODY of my customers, when talking in English about machine productivity is talking about "details per minute". LOL
And more fun thing is that "detaļa" is homonym. Guess what is other meaning - yeah it is "detail"
At least when talking in English about spares we speak correctly - "spare parts" not "spare details"
In Latvian it would be "rezerves detaļa" - somehow tempting