thought /
t/ noun
STH YOU THINK
1 [C] ~ (of sth / of doing sth)| ~ (that ... ) something that you think of or remember: I don’t like the thought of you walking home alone. 
She was struck by the sudden thought that he might already have left. The very thought of it makes me feel sick. I’ve just had a thought (= an idea). Would Mark be able to help? It’s just a thought. ‘Why don’t you try the other key?’ ‘That’s a thought!’ All kinds of thoughts raced through my mind. I’d like to hear your thoughts on the subject.
MIND / IDEAS
2 thoughts [pl.] a person’s mind and all the ideas that they have in it when they are thinking: My thoughts turned to home. You are always in my thoughts.
PROCESS / ACT OF THINKING
3 [U] the power or process of thinking: A good teacher encourages independence of thought. She was lost in thought (= concentrating so much on her thoughts that she was not aware of her surroundings).
4 [U] the act of thinking seriously and carefully about sth 
consideration: I’ve given the matter careful thought. Not enough thought has gone into this essay.
CARE / WORRY
5 [C] ~ (for sb/sth) a feeling of care or worry: Spare a thought for those without enough to eat this winter. Don’t give it another thought (= to tell sb not to worry after they have said they are sorry). It’s the thought that counts (= used to say that sb has been very kind even if they have only done sth small or unimportant).
INTENTION
6 [U, C] ~ (of sth / of doing sth) an intention or a hope of doing sth: She had given up all thought of changing her job. He acted with no thoughts of personal gain.
IN POLITICS / SCIENCE, etc.
7 [U] ideas in politics, science, etc. connected with a particular person, group or period of history: feminist thought
—see also think v. 
have 
second 
thoughts to change your opinion after thinking about sth again: You’re not having second thoughts about it, are you? on second thoughts (BrE) (NAmE on second thought) used to say that you have changed your opinion: I’ll wait here. No, on second thoughts, I’ll come with you. without a second thought immediately; without stopping to think about sth further: He dived in after her without a second thought.—more at collect v., food, pause n., penny, perish, school n., train n., wish n.