adjective
organic, bio (short for biological)
B1
'bio' in German usually means 'organic' (organic food) or as short for 'biological'. It's an adjective and also a common prefix (Bio-) in compounds like 'Bio-Lebensmittel'. It is not gradable (no comparative/superlative forms). No reflexive or special preposition; typical label in product descriptions.
Examples
Ich kaufe nur bio-Obst auf dem Wochenmarkt.
I only buy organic fruit at the weekly market.
Viele Supermärkte bieten inzwischen ein eigenes Regal für bio-Produkte an.
Many supermarkets now have a dedicated shelf for organic products.
Die Familie kaufte bio-Gemüse, weil es gesünder schien als konventionelles Gemüse.
The family bought organic vegetables because they seemed healthier than conventional ones.
Details
Mnemonics
a green label with the letters BIO slapped onto fruit or packages
same as English 'bio' (as in biology) — think 'biology' = life
Notes
'bio' is an informal/marketing abbreviation of 'biologisch'. It is commonly used in everyday speech and on product labels.