side effect

Translations
побочный эффект
The medication has a side effect of drowsiness.
У лекарства есть побочный эффект в виде сонливости.
Definitions
A side effect is an unintended and often adverse effect that occurs in addition to the desired therapeutic effect of a drug or treatment. Side effects can also refer to any secondary or indirect consequences of an action or decision.
Words
side

adjective
побочный
effect

noun
эффект