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.
1. of, relating to, or characteristic of the basic or inherent constitution of a person or thing; fundamental: a radical fault. 2. concerned with or tending to concentrate on fundamental aspects of a matter; searching or thoroughgoing: radical thought; a radical re-examination.