For example, with the adjective halb:
...ein halber Teelöffel über drei Stücke Wurst.
... a half a teaspoon on three pieces of sausage.
Caption 39, Currywurst - Berlins schärfstes StückPlay Caption
So ein halber Marathon sind 20 Kilometer.
Such a half marathon is 20 kilometers.Play Caption
Ein halber Mond versinkt vor mir.
A half moon sinks before me.
Caption 17, Tokio Hotel - Durch den MonsunPlay Caption
From knowing that the adjective halb, seen here as halber, means "half," you might make a mistake when you see a word of the same spelling in some other contexts:
Der Ordnung halber...
When you find a noun in the genitive case followed by halber, this is the preposition halber and means "for the sake of..." The above could be translated as "for the sake of orderliness" or "for the sake of clarity." Here are few other examples:
Der Einfachheit halber = for the sake of simplicity
Der Transparenz halber = for the sake of transparency
Der Vollständigkeit halber = for the sake of completeness
Der Datenqualität halber = for the sake of data quality
Der Ehrlichkeit halber = for the sake of honesty
In some cases, the use of the adjective halber became so common that it fused with a noun to become an adjectival suffix, or the ending of an adjective. The meaning that the suffix -halber lends a word is usually the same as the adjective:
gerechtigkeitshalber = der Gerechtigkeit halber = for the sake of justice
sicherheitshalber = der Sicherheit halber = for the sake of security
But sometimes it can have a slightly different meaning as the cause of something rather than for the sake of something:
krankheitshalber = because of illness
umständehalber = due to circumstances
Go to the German Duden dictionary and read the definitions of the adjective halber and the adjectival suffix halber. See if you can translate the title of this lesson to proper German, too! (Hint: it will use the genitive case of das Deutschlernen.)