5 ADV You use then at the end of a topic or at the end of a conversation. □ 'I'll talk to you on Friday anyway.'—'Yep. Okay then.'
6 ADV [adv ADV ] You use then with words like 'now', 'well', and 'okay', to introduce a new topic or a new point of view. □ Now then, you say you walk on the fields out the back?
7 ADV You use then to introduce the second part of a sentence which begins with 'if'. The first part of the sentence describes a possible situation, and then introduces the result of the situation. □ If the answer is 'yes', then we must decide on an appropriate course of action.
8 ADV You use then at the beginning of a sentence or after 'and' or 'but' to introduce a comment or an extra piece of information to what you have already said. □ He sounded sincere, but then, he always did.
9 now and then → see now
10 there and then → see there
thence /ðe ns/
1 ADV [oft ADV before v] Thence means from a particular place, especially when you are giving directions about how to get somewhere. [FORMAL , OLD-FASHIONED ] □ I ran straight up to Columbia County, then turned East, came down the Harlem Valley and thence home.
2 ADV [oft ADV before v] Thence is used to say that something changes from one state or condition to another. [FORMAL , OLD-FASHIONED ] □ …the conversion of sunlight into heat and thence into electricity.
thence|forth /ðe nsfɔː r θ/ ADV Thenceforth means starting from a particular time in the past that you have mentioned. [FORMAL ] □ My life was totally different thenceforth.
the|oc|ra|cy /θiɒ krəsi/ (theocracies ) N‑VAR A theocracy is a society which is ruled by priests who represent a god. [TECHNICAL ]
theo|crat|ic /θiː əkræ t I k/ ADJ [usu ADJ n] A theocratic society is ruled by priests who represent a god. [TECHNICAL ]
theo|lo|gian /θiː əloʊ dʒ ə n/ (theologians ) N‑COUNT A theologian is someone who studies the nature of God, religion, and religious beliefs.
the|ol|ogy /θiɒ lədʒi/ N‑UNCOUNT Theology is the study of the nature of God and of religion and religious beliefs. □ …questions of theology. ● theo|logi|cal /θiː əlɒ dʒ I k ə l/ ADJ [usu ADJ n] □ …theological books.
theo|rem /θiː ərəm/ (theorems ) N‑COUNT A theorem is a statement in mathematics or logic that can be proved to be true by reasoning.
theo|reti|cal /θiː əre t I k ə l/
1 ADJ [usu ADJ n] A theoretical study or explanation is based on or uses the ideas and abstract principles that relate to a particular subject, rather than the practical aspects or uses of it. □ …theoretical physics.
2 ADJ [usu ADJ n] If you describe a situation as a theoretical one, you mean that although it is supposed to be true or to exist in the way stated, it may not in fact be true or exist in that way. □ This is certainly a theoretical risk but in practice there is seldom a problem.
theo|reti|cal|ly /θiː əre t I kəli/ ADV You use theoretically to say that although something is supposed to be true or to happen in the way stated, it may not in fact be true or happen in that way. □ Theoretically, the price is supposed to be marked on the shelf.
theo|reti|cian /θ I ə rət I ʃ ə n/ (theoreticians ) N‑COUNT A theoretician is the same as a theorist .
theo|rist /θiː ər I st/ (theorists ) N‑COUNT A theorist is someone who develops an abstract idea or set of ideas about a particular subject in order to explain it.
theo|rize /θiː əra I z/ (theorizes , theorizing , theorized ) in BRIT, also use theorise VERB If you theorize that something is true or theorize about it, you develop an abstract idea or set of ideas about something in order to explain it. □ [V that] Police are theorizing that the killers may be posing as hitchhikers. □ [V + about ] By studying the way people behave, we can theorize about what is going on in their mind. [Also V ] ● theo|riz|ing N‑UNCOUNT □ This was no time for theorizing.
theo|ry ◆◆◇ /θ I ə ri/ (theories )
1 N‑VAR A theory is a formal idea or set of ideas that is intended to explain something. □ [+ of ] Einstein formulated the Theory of Relativity in 1905.
2 N‑COUNT If you have a theory about something, you have your own opinion about it which you cannot prove but which you think is true. □ There was a theory that he wanted to marry her.
3 N‑UNCOUNT The theory of a practical subject or skill is the set of rules and principles that form the basis of it. □ He taught us music theory. [Also + of ]
4 PHRASE You use in theory to say that although something is supposed to be true or to happen in the way stated, it may not in fact be true or happen in that way. □ A school dental service exists in theory, but in practice, there are few dentists to work in it. COLLOCATIONS theory NOUN 1
noun + theory : chaos, quantum, relativity; management
adjective + theory : economic, evolutionary, Marxist, political; classical, linguistic, literary, scientific
verb + theory : apply, develop, formulate, test; challenge, dismiss, disprove, reject; prove, support
thera|peu|tic /θe rəpjuː t I k/
1 ADJ If something is therapeutic , it helps you to relax or to feel better about things, especially about a situation that made you unhappy. □ Astanga Yoga is a therapeutic physical exercise that focuses on breathing and relaxation.
2 ADJ [usu ADJ n] Therapeutic treatment is designed to treat an illness or to improve a person's health, rather than to prevent an illness. [MEDICAL ] □ …therapeutic drugs.