"A peripheral or secondary effect, especially an undesirable secondary effect of a drug or therapeutic regimen."
Of the most common side effects of Nexavar, I have nine (so far). Some side effects develop weeks into the therapy.
intestinal problems
bleeding gums
internal bleeding
facial erythema
cramping
tender, itchy scalp
fatigue
"chemo voice"
chills
Of these, fatigue, the facial rash, the cramping, the hoarse voice and the tender scalp are the most bothersome to me.
There are also several much more severe side effects which are less common. Fortunately, I have none of those (so far).