Results for: radical
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
3. (Government, Politics & Diplomacy) favouring or tending to produce extreme or fundamental changes in political, economic, or social conditions, institutions, habits of mind, etc a radical party
4. (Medicine) Med (of treatment) aimed at removing the source of a disease radical surgery
5. Slang chiefly US very good; excellent
6. (Life Sciences & Allied Applications / Botany) of, relating to, or arising from the root or the base of the stem of a plant radical leaves
7. (Mathematics) Maths of, relating to, or containing roots of numbers or quantities
8. (Linguistics) Linguistics of or relating to the root of a word
1. (Government, Politics & Diplomacy) a person who favours extreme or fundamental change in existing institutions or in political, social, or economic conditions
2. (Mathematics) Maths a root of a number or quantity, such as 3√5, √x
4. (Linguistics) Linguistics another word for root1 
5. (Linguistics) (in logographic writing systems such as that used for Chinese) a part of a character conveying lexical meaning
[from Late Latin rādīcālis having roots, from Latin rādix a root]
radical /rdkl/ n. a person with very strong nontraditional beliefs, esp. s.o. who wants change in politics or religion: Radicals won several seats in Parliament this year.
adj. 1 having very strong nontraditional beliefs, ideas: Radical students protested the Presidents visit to their college campus. 2 very unusual, different from what is normal: We noticed a radical difference in our sons behavior after he finished college and got a job. -adv. radically.