1. Not reversible or capable of having either side out
   - nonreversible 
2. Involving only one part or side
   - unilateral 
3. Favouring one person or side over another
   - biased, colored [US], coloured [Brit, Cdn], slanted 
4. Poorly balanced or matched in quantity or value or measure
   - unequal

See also: anisometric, equality, incommensurate, mismatched, nonequivalent, odds-on, one-party, partial, unbalanced, unequalised [Brit], unequalized, uneven, unsymmetrical

Encyclopedia: One-sided

• shoal
• shoaly
• shoat
• shock
• shock absorber
• shock therapy
• shock treatment
• shock troops
• shock wave
• shock-absorbent
• shock-headed
• shockable
• shocked
• shocker
• shocking
• shocking pink
• shockingly
• Shockley
• shockproof
• shod
• shodden
• reef knot
• reef squirrelfish
• reef whitetip shark
• reefer