If you have allergies, pregnancy can make your symptoms worse. But you're right to worry about taking allergy medicine during pregnancy. Pregnant women shouldn't take some allergy drugs. Certain antihistamines, however, are safe.
free radical. (chemistry). An atom or a diatomic or polyatomic molecule which possesses one unpaired electron. Also known as a radical.ree radical. in chemistry, a molecule or atom that contains an unpaired electron but is neither positively nor negatively charged. Free radicals are usually highly reactive and unstable.
From Wikipedia: the term Radical (latin radix meaning root) has been used since the late 18th century as a label in political science for those favouring or trying to produce thoroughgoing or extreme political reforms which can include changes to the social order to a greater or lesser extent.