To think, reflect, meditate, ponder; bithinken right, wel, think hard or carefully; -- usually refl.; -- (a) alone; (b) with of, on, to, upon phrase.
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(a) To be aware of (sth.) as a fact; know (that sth. is true, has happened, etc.); (b) with that clause or pronoun and that clause; (c) with who, which, what, when, wher, hou, or whi clause; (d) with……